I realize this is going to sound nerdy... but "nerd" is a description I gladly accept.
Serve your food on hot plates.
No, not ice cream and salad... but anything that you'd like to have arrive hot or warm in someone's mouth... HOT PLATE!!
I've always known that some fussy types (read... THE FRENCH) were big on warmed plates... and that always seemed just a little too TOO to me. But then, years ago, I began working with Marcia Kiesel at Food & Wine magazine. Now, from the start, I knew that woman could COOK. But I started to notice that she never plated the recipes she was testing without heating the plates first. So I started to wonder if, just perhaps, it wasn't a French affectation, but maybe something with a purpose.
It started to make sense: keep the food the way you took it off the stove... don't change everything by putting it in/on a serving vessel 20-30-40 degrees colder. And once I accepted the idea behind it... that was it. I no longer serve hot food on anything but a warm or even very warm plate. And it's easy to do...
If your oven is on, put the plates in for a few minutes. If the oven isn't in use, nuke the plates for a minute (make sure your plates are microwave safe!!). Or if none of these options is available... a sink full of hot water works. Yes, you'll have to dry the plates! I even know some people who run the plates through a hot rinse in the dishwasher (if they have to do A LOT of plates for a party). However you do it... heating your plates is one of those things that changes your food... and your diners will notice.