I've found a solution, at least for some metal bracelet watches, esp useful if the body of the watch is heavy. The key is to have the semi-curved rigid clasp that sits on the underside of your wrist (usually several links long) act as an anchor because it tends to stay on the semi-flat undersurface of the wrist. .
1- If the bracelet is the correct size for your wrist remove a link(s) from the radial (thumb) side of the bracelet and insert it on the ulnar (little finger) side of the bracelet.
2- If the bracelet is too large remove a link(s) from the radial side and store it.
It's worked well for me on two bracelet watches.
I don't have a solution for non-bracelet watches - leather, rubber, etc.