I also remember a couple of Canadian shooters who must have memorized the rulebook so they could lodge a protest on each others most insignificant infringement. It made for some entertaining matches at Custer, Washington.
There is a number of things you can do.
Use a 2 lb weight and hold your arm out, while visualizing your shot plan.
Get either a squeeze ball to exercise your hand, or get one of those spring loaded finger exercise tools.