ddiddler -

I'm a strong believer in using a strap. I also believe posture is super important, not only to prevent stffness and aches but also to assist proper hand position which in turn improves reach. Proper posture is important to singing, too.

But don't ignore stretching exercises. Just as hands benefit from stretching and warm-up prior to and during practice, so too does the rest of the body. Take a look at movements such as trunk bends and twists, toe touches, and various head/neck movements.

I generally break up my practice time into 30 minute segments and during the breaks I'll do one of the exercise types above. Although the stretching break lasts less than five minutes, I find it very refreshing and it gets rid of muscle tension and prevents stiffness.