Wetness is my biggest factor. When riding outdoors I use little to no "chamois cream" since my sweat doesn't build up enough to cause any chafing. Indoor sessions, however, are another story. I can saturate an entire kit and fill my shoes with puddles of sweat in a matter of an hour. Chamois Butt'r has been a tremendous savior. I apply generously where I'd be getting chaffed and then there are no worries.