Carpentry. Carpentry is a extremely satisfying artform. Although there is a lot of sweat and hard work involved, it really is satisfying seeing a pile of wood planks be turned into something that can be used, but also is beautiful. Whether it be a table or a chair, seeing this process is very gratifying; it makes you take a step back and admire both nature and man, working together to create art.
Ahhh... Art. Both stressful and relaxing at the same time. You screw up somewhere, it is extremely stressful. You don't screw up, you're relaxed. Though sometimes it can be difficult and rough, the final product may actually be what you wanted. To imagine you created a may or may not be masterpiece out of four tubes of paint. It feels like an accomplishment. Except a lot of the time it doesn't.
Puzzles & Mazes
Drawing mazes and typing up/creating puzzles is both relaxing and enjoyable. Whether it be on a 100 degree day in a 92 degree room, or a 60 degree day in a 62 degree room, having headphones, classical piano playing, graph paper, a ruler, and a mechanical pencil really hits the spot. One can sit there, for hours, just sketching and drawing lines, and that can be very unwinding after a tiring day. Plus, one can get an awesome maze or a confounding set of puzzles out of being relaxed.
Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own. (Matthew 6:34 NIV)