Biggest tip I was told about riding in the rain, is too take it easy. Don't push yourself or the bike. Don't stab hard on the brakes or gun the gas. Just be smooth.
Oh and we had a wicked ride back from Dinqua's rally one year, heavy rain, hail, miserable. Uncle Charlie decided he'd sleep for a another couple hours. He had the same ride, just sunny. So sometimes it worth pulling over and waiting.
