hi xigeon, we use a product called aviform ultimate it contains a number of things including - multi vits,water sanitizer, etc. we use this product 3/4 times a week.
when we're in the racing season we feed a diet that's quite high in carbs but as we get towards basketing night we give a high fat seed mix. there will also have access to seeds which are high in protien if they want them.
to get them ready for a race- we keep the cocks(males) and hens(females) seperate through the week and on basketing night we let them see their mates for a short period to increase their motivation to get home as quick as they can.(when they return from a race they get to spend some time with their mate and they quickly learn this).
on race days i can't wait normally, as soon as i wake up i'm thinking about it, first off checking the weather, then phoning lib line to see what news there is at the lib site. then i get all the other birds fed off out the way. put fesh food and water ready for the birds due to return, check the clocks still working ok, then put it in the loft ready. i'll work out what time i think they'll be back and have their mates waiting for them when they get back. i've still normally got hours to go after doing this so then it's smoking like a trooper drinking coffee like it's going out of fashion and pacing back and fore the garden whatching everything that fly's. hope this helps.