Normally just water or diluted juice sometimes with a bit of added salt and sugar depending on requirements, sometimes a Nuun tablet or two added to the bottle if I'm touring in hot weather (because they are easy to carry more than for any other reason). Pretty much the same for racing as it goes although I don't do this much now and don't do long events (so far not more than 50 miles).
After a race I have a habit of packing a couple of small cartons of milkshake or soya shake.
After a race I have a habit of packing a couple of small cartons of milkshake or soya shake.