You could try slightly cooler water, or as Siguy says try adding ingredients to make an "uberlather" (geez I hate that word), the basic ingredients being shaving soap, shhaving cream and glycerin (also called glycerol) though I like to add some vitamin e based moisturising cream or Nivea sensitive, I also cold water lathered this too.
Recently though I got given a jar of Martin De Candre which performs very nicely in it's own right, and likes warm/hot water.