I'm a kayak fisherman, so getting back quick is not really an option. For me it's all about being observant. Check the hourly forecast ahead of time, know when the highest storm chances are, and plan your trip around that. Storms here almost always come from the west, so CONSTANTLY check the sky in that general direction while you're out. If I see ANYTHING start building that way, I usually go ahead and start working my way back to the ramp so that I can get out quick. You can always fish around the ramp area until it gets closer, then you maximize time on the water without being overly risky.
"You can’t get second things by putting them first; you can get second things only by putting first things first."
- C.S. Lewis