i do the entire thing in cycling shorts with a thin chamois. i have yet to purchase tri shorts or a wetsuit.
T1: dunk feet in a bucket of clean water to get the sand off, quickly dry them and put on socks, cycling shoes, shirt, helmet, sunglasses and take a gel.
T2: take off helmet, swap to running shoes, take a gel and go.
i have everything organized on a towel in the order ill be needing it.