Sleeping feels really great when you are starting to get stressed. I generally sleep at night when I have all my work done. You just relax and start to drift off. Sleeping can be done virtually anywhere, and most people won't mind if you do it if you have all your work done. Sleeping also takes no energy to do, so it's my favorite.
I also like to shower. Showering feels great if the water is at a luke warm temperature. Showering is great because like sleeping, you get an opportunity to do it at least once a day, and no one has a problem with you doing it. People actually encourage it. It not only de-stressifies you, but also increases personal hygiene. The only problem with it is that it wastes valuable fresh water, so you shouldn't take really long showers.
The final way that I like to relieve stress is by engaging in mindless activity. This can be a lot of things. It can be watching a movie, playing video games or reading a book. These activities generally don't take very much brainpower, (unless the book really advanced) are really relaxing, and are generally entertaining. This form of stress relief is the least advised. If you are stressed, it generally is because some thing is due or work has to be completed. These activities take up a lot of valuable time that probably should be used to finish your work instead. If you have work to do, then you should complete it before you engage in any of these activities.
These are the three ways that I like to relieve stress by. Snoozing, taking a bath, and participating in activities that generally take relatively little thinking power. Some of these are better than others and take less time, but they all work for me. I hope that some of these are useful to you so you don't get too stressed out, which can be very bad.