The Proofing List. From the list members at LittleGenius.

FOOD:
Food on floor/mats
Active baiting in breed ring next door
People/dogs eating near ring
Popcorn/hotdog pieces falling into ring
Drinks spilling
Concession stand nearby
Box with judge's refreshments under the table at ring entrance

SOUNDS:
Squeaky toys
Keys jingling
Whistles
Slamming large doors/stadium seats
Dogs barking, yipping, howling, whining
Kids playing, teenagers running, babies crying
Loud angry-sounding people (harsh correction given nearby)
Food container sounds: crinkle of bags, rattling of bottle/metal bowls,
biscuit box/can, digging in ice chest, dumping ice
Balloon's squeal when rubbed
Loudspeakers, incl. that whining noise
Buzzing of clippers, blow dryers
Beeping of watch/alarm clock
Ticking of kitchen-timer
Car alarms
Other's clicker
Generator
Highway noise
Gunshots/car-backfiring
Vehicles (car engines/doors slamming, motorcycles, planes/helicopters, large
growling-squealing trucks)
Sirens from emergency vehicles
Trains (can make a building shake)
Chairs moved noisily at ringside
Clapping, cheering (conformation group judging)
Coughing, sneezing, nose-blowing
High-pitched baby-talk; very-deep voice
Someone else giving the same command you are about to give (anticipation)
Someone else calling your dog's name, esp. followed by a command
Bouncing basketballs
Dumbbell hitting high jump (not yours, of course<g>)
Motorized wheelchairs
Model airplanes flying (noisy, interesting "birds)
Helicopters
Bicycle/motorcycle riders
Stormy weather, thunder (if your dog is not phobic)
Drains covered by metal grates (they rattle and gurgle under the mats)

PEOPLE:
Various sizes/ages (very large, very small, kid as figure 8 post, big hair, hats)
Sitting/playing at ringside
Using wheelchairs, walkers
Hands in/near pockets (must have bait, no?) or holding hand up as if baiting
Dog's human friends talking, laughing, clapping, motioning, saying dog's name
Smokers
Kids stooping and calling doggie
Kids sitting in a line (on the ground, at dog level) slurping ice cream
Someone saying word that excites dog ("kitty" "treat" "ball", etc)
Wearing various hats, raingear w/ hoods
Taking pictures/videotaping
Show photographer w/flash, toys

JUDGES/STEWARDS:
Wearing various hats, beards/mustaches, clicking high-heels, squeaky
tennis shoes, long skirts/overcoats flapping
Clipboard held in various positions, incl. stand-for-exam
Clicking of pen or counter
Standing/moving unusually close to dog in various exercises
Standing/moving very near articles, dumb bell, jumps, etc.
Touching your scented article
Placing articles after having eaten lunch, but not having washed hands
Umm.. male dogs and female figure-8 posts
Judge run up just in front of you then walk backwards facing you as you heel forward
Figure-8 posts squirming, hands/arms in various positions
Suddenly walking/jogging across ring, or near you dog (esp. the opposite direction)
Jewelry, charm bracelets, necklaces, scary earrings (esp. stand-exam)
Perfume, smokers
Too jolly or fierce demeanor in the judge's carriage/voice
Anticipation of judge's order
Judge raising hand to call out-of-sight handlers back in
Rustling clothing (dog knows judge behind her gave a signal, so downs).
Long pause before judge's commands for signals, retrieves

HANDLER:
Twitching/extraneous movements (vs. "real" signal)
Running into ring-gate/wall.
Slightly adjusting position as you face the dog on the recall
Heeling up to a jump ( judge's mistake -- or not)
Being all warmed up and ready to go and then having to wait
Going in sooner than expected (before you do your warm up)
Having to suddenly stop an exercise, then restarting (interruption of flow)
Dumbbell re-throws

OTHER DOGS:
Running, playing, bouncing up & down nearby
Jumping over ring gate into your ring
Reaching under ring gate to get their dumbbell
Pushing back ring gate on a go-out
Of various sizes, appearances (Poodle in show cut, tiny Chihuahua, Great Dane)
Another dog coming into the ring, picking up your dog's dumbbell

STAYS:
Being very close to next dog
Next handler leaving/returning very close to your dog
Steward removing dog from line
Visiting neighbor, scooting closer, reaching to sniff
Dogs next to yours changing position, leaving place
Other dogs being corrected (in matches)
Handler to left with treats in pocket

MISC:
Livestock sounds/smells/sights, Birds
Rabbit/horse/sheep droppings in the ring
Agility or Lure coursing or Herding on grounds
Ceiling/floor fans
Lights going off
All sorts of backdrops dog must go to (behind you on signals, recalls;
go-out spots, dog's view behind/beside jumps.
Dumbbell landing under baby gate/judges table, close to jump, to the side.
Go-outs to gate with stanchion off-center
Other dumbbells flying into your ring, or hitting the ring-gate
Tents flapping
Utility training: Throwing glove #2 and then sending to #3
People on horseback
Working on recently soiled area: sitting/lying, retrieving/scent articles
Colored dots/chalk marks on floor (for marking fig 8 locations, etc)
About-turns right at the ring entrance.
Stuffed toy on ground/chair or vendors rack nearby
Ring cleaned with Lysol after an accident
Basketball hoop netting at end of gym
Dumbbell after another dog was mistakenly given yours to use
Sawdust, red dirt, etc. under/on dumbbells/gloves/articles
Touching of dog's tail/body during stays
Bird landing on jump just as you send dog (unusual appearance of jump)
Jumps not on level ground (lengthwise and crosswise)

TRACKING:
Rain, snow, sleet, hail, wind, etc
Puddles, mud, fallen branches
Debris along the track (especially white!)
Having a party of at least three following behind - two judges and the tracklayer
Misc. folks near track
Animal carcasses near track
Tracking line becoming entangled
Dog restarting after untangling line, removing stickers, giving water
Terrain: pokey grass, stickers,
Cross tracks (critter or human) can inadvertently happen at TD tests
Livestock (horses, cows, geese, ETC) and birds
Mice/ground critters
Bumps/lumps in ring matting, uneven ground
Tall grass, dry pokey grass
Those little yellow butterflies that play close to the ground
Windy conditions (wind, fans) esp. scent articles
Shadows across ring (see note at end of list)
Lines on floor/blacktop (dog may jump them while heeling, or
misjudge while jumping if the lines are parallel with a jump takeoff or
landing, but at the wrong location.)

ACTIVITY:
Ring gates falling over
Balls/toys/dumbbells bouncing, rolling, thrown
Dogs jumping/moving in next obed/conformation ring
People hauling crates/dollies thru nearby doors, setting up crates, etc.
Nearby door suddenly propped open
Things blowing/running across ring: wrappers, balls, mice, lizards, another's
dumbbell, balloon, armband
Birds nesting material floating down
Taped/tacked-up banner falling off wall
Umbrellas
Blanket/sheet being shaken out (to cover something)
People putting coats on
Pooper-scooping (smell of "oops", sound of metal scoopers, smell of disinfectant)
Balls/frisbees/toys thrown nearby
Equipment/tables being moved/dropped/dragged
Movement/noise from raised stadium seating
Ring ropes swaying, kids playing with them
Terriers being sparred next to obedience ring

AGILITY:
Gate Steward's white board falling over as you start
Another dog entering your ring to play on your dog's time
People inside ring resetting jumps/chute, sitting/drinking/eating/talking
Judge raising arms, signals to scribes
Judge following closely on contact obstacles
Various shapes of jump wings (shaped like animals, a rainbow they could go under, faces painted on them,etc)
Barrels that make noise when wind blows across them
Various weave poles setups, incl. tape across the base, not exactly in straight line

PROOFING:
Generally, proofing for what might really happen is worth the time. Overdoing with crazy stuff can lead to stress and poor attitude. Remember out-of-sit stays, to proof for when you're not there.- you don't 'have to actually proof for everything we list here. You proof for everything you can come up with. Then, when the dog sees something he's never see in proofing, he's so used to the 'game' that he just acts like 'oh this is another one
of mum's things.

 And always keep your proofing positive. There is no profit in frightening a dog, or then becoming annoyed and correcting harshly.  If anything does spook your dog, do "the jolly routine" instantly, and your dog will not become traumatized.  Proof will real things that the dog can figure out will not really harm him

PLACES TO PRACTICE:
Banks, parks, schools, shopping centers, pet stores, horse stables, livestock area, fairgrounds, restaurant parking lot, outside vet clinic, soccer games, airport underground walkways during off-hours, rented rings, horse arenas, parking garages, near ATM machines, elevators, others' back yards.

Warm-Ups:
Game of tug, fronts/finishes, quick sits, tug again.

Shadows in Ring:
- the shadow problem is bigger than we sometimes realize. I repeatedly observe dogs sitting crookedly at heel, but perfectly aligned with the shade;  also, I once judged a large Utility Class all morning. When the class started, the whole ring was shaded by a line of tall trees. As the morning progressed, a triangle of sunlight appeared in the far right corner.  As it grew to cover the right hand jump, it made a distinct demarcation of light and shade down the ring center.  By mid-morning almost all the dogs angled left between the jumps, following the line of shade.  By noon, none were passing, since the shade did not reach the line of the jumps.

ON SHOW DAY:  Get to the show early, watch your ring, and see what seems to be getting to the dogs.  You can cope with some of the more outlandish things on the day of the show by recognizing them early enough to expose your dog to them BEFORE he's in the ring.  For example, when the bicycles showed up, I made sure I sat my dog next to the bike path to let him get a look at them and see if they'd bother him.  I heeled him right next to the generator until he seemed desensitized.