One of the things I like to do is hit the pool whether it's one the heated community pools maintained by my homeowners association or my own, for me, jumping in the water is the best way to unwind.
The best part is it costs nothing or next to nothing and helps me to burn off energy if I decide to swim. It can also be extremely relaxing if I just want to pull out our giant floater. Add a book (another great way to unwind) and I'm good for hours. (I slather on a ton of sunscreen, of course)
Also, I noticed when I chill out by watching television, I tend to want to reach for food. Not sure if you're a big television watcher but keeping it off is a great way (for me) not to gravitate toward the fridge.