If you want to increase antler size and body size you need to supplement with a high-protein feed such as alfalfa pellets or even peanuts (if you have access). Food plots can be planted to grow the right crops if you have enough land & ambition. The most important time to supplement deer to increase body mass is when their natural feed is at its' worst, late winter in most areas. The most important time to feed for antler growth is when they are growing, in early summer.
Then supplement with minerals using mineral blocks, licks, etc. to be sure deer are getting all the nutrition they can use.
Another way to help deer grow is to treat them for parasites and insects by adding a rub-applicator to your feeders in the off-season. No animal full of parasites & covered in insects will grow as fast as one without these stressors.
The hardest part of maximizing deer antlers & body mass is to hold off shooting until the deer are at least 5 years old. In most areas deer don't max out body & antler size until year 7 or 8, so shooting young bucks guarantees you'll be shooting bucks with smaller bodies & racks than you could be.
Early season and post-rut attractants are almost always food scents while the rut means sexual attractants.
