Before any practice or playing, do warmup/stretching.
In a warm-up, focus on the motion. Make it fluid and let it feel good. Do not hold position nor test your limits.
Another good stretch/warm-up tool is to just shake fingers, wrists, arms and shoulders.
Stretch the muscles after playing if they are stiff.
Put your legs in a natural position. Lift the toes as high as you can, keeping the heel on the flor. Do quick taps, keeping the feet up. Play 8th notes (while hands do 16th notes).