I used to have the fastest T times in most of my races. Here’s a few things to consider.
T1-
learn to strip your wetsuit hard and fast. After you peel off the top while running, get ready for one or two big pulls down to get it below your knees. Step up and down in the legs to remove them the last bit. Learn to do this without your hands and you can get started putting on your helmet at the same time.
You dont have to clip your helmet until you’re mounted so if the transition area allows, learn to clip it with one hand as you run with the bike.
learn the running mount and get going. Dont put your feet in the shoes until you get going well and have the room to do it well and fast. if you can, get it done going on flat land or downhill. never on the uphills.
Have all your food/gels whatever for the entire race mounted on the bike (oly and shorter races) shove gels up your pant leg and in pockets. Come in handy when you get to the run. Glasses, if you use them, should be on the bike. I usually could hang them off the brake cables.
T2
get you feet out of the shoes as close to t2 as you can. again, try not to do it on uphills. if you can preride, find the best shoe strip areas before the race. Go hard till you get to the dismount line. Brakes are there for a reason, use them to slow down to a runnable speed and use the “shoot and catch” dismount. with the pedals level, apply a hard push with the leading foot and shoot the bike out in front of you. Catch the seat and go. you’ll hit the ground running and look cool doing it. DONT DO THIS WITH BEHIND THE SADDLE BOTTLES. Dont need them in short races anyway.
unclip your helmet while running to the rack. you can even put it on you bars of your good. it should be off by the time you rack the bike.
Running shoes first. This is where I saw the most trouble. Proper form is to grab the tongue and the heel and force the foot in BEFORE it reaches the ground. Like putting on jeans, you dont step on the shoe before its all the way on. DO NOT SIT DOWN
The only other thing to grab is your # and maybe a hat. Remember, you got your food on the bike. Keeps it easy and also makes sure that you dont forget anything.
I think that about sums it up for me. For short races, this is the best transition I was able to think of. For 1/2’s and IM’s, the potential cost of not putting on socks or not having the proper nutrition far outweighs the speed of the transition. Make it fast by using the sock condom thing already posted and other small tricks but for the most part, its the same.
The most important part is to PRACTICE these things in training. Durring good weather days I started and ended every ride with my shoes in the pedals. Those things didnt come unclipped for weeks at a time. This really is a skill and should be treated as such. It’ll make you safer as well.