You should always start with hot food, because cold or room-temperature foods cannot be heated, warmed, or cooked in the warming drawer. Bacteria can grow quickly when food is left between 40 and 140 degrees, which would put a real damper on that dinner party.
Also, not EVERY oven has the warming feature, so be sure to solidify that detail before you stick hot food in a drawer and wonder why it gets cold. (I checked. I actually don’t have this warming feature, just a broiler, so there go my plans of culinary greatness.)
With that said, go ahead and keep your pans in the drawer if you want. But if you’re hosting some friends and want to keep those waffles warm while you bake up some scone, now you know just how you can do it.