One of the best ways to shave off time while racing is to fine tune your skills in transition. This means practicing over and over until you don't have to think about what you are doing - it just becomes second nature. In order to do this, keep a very minimalistic approach to your transition zone. You have to remember that this is a race, so there is no need to wash every blade of grass off your feet or wipe off every drop of water. In fact, embrace the idea that your body (especially your feet) will be a bit dirty after your race. That will eliminate the need to have wash basins with water in them, towels to dry off your feet, hand sanitizer to clean your feet, blow dryers to dry your hair...or whatever else you may think you need that is making your area cluttered.
Think about using just the essentials. Here is a very simple way to get that accomplished. First, lay down a towel. A small hand towel will work. It should be just large enough to hold your bike shoes and running shoes or maybe even a bit smaller. Put your bike shoes on the front edge of the towel closest to where you plan to stand during T1. Next, place your helmet on top of your bike shoes (so you don’t forget to put it on). You have now set up everything you need for T1.
Sunny day and want a pair of sunglasses to wear while you bike? Open them and put them inside your helmet. Better yet, attach them to your bike with a small piece of tape. That way once you are up and riding, you can simply pull them off and put them on.
Next, place your running shoes in front of your bike shoes (closest to the bike rack); then, place your race belt with bib number on top. Some races will require you to wear your bib for bike and run. If that is the case, put your race belt in your helmet and as you put on your helmet, put on your race belt as well. T2 is now set up. When you come into T2, rack your bike, unclip your helmet, and as you bend down to take off your bike shoes, place your helmet on the ground while you reach for your race belt and running shoes. Put on your running shoes and start to run out of T2 as you put on your race belt.
There are other ways to shave off of time from T1 and T2 like having your shoes attached to your bike, but it is important to first master a simple transition zone.