Considering a Compttion - Saturday Afternoon

What could be a usefull plan to be followed last week until a race, considering that competition would be only 100m ( with heats ) saturday afternoon ?
I know that each sprinter follows his own way but what are the general rules
energy suplies ( foods: what ? when ? how much ? )
rest management ( sleep just before comp ? how many hours at least ? any medicinal to get in sleep easily ? )
training ( what should be done days before the competition ? )

Probably this is not too easy to be answered cause there are so many variables to consider, but, what could be a general plan ?