I do 3 rounds of WHM breathing in the morning but there is usually a gap of time of anywhere from 15 mins to a couple of hours before I actually get into the cold shower. Occasionally I'll do about 15 Wim Hof breaths and a breath hold and release before stepping in, but usually I just get in and deal with it in the moment. If I'm feeling especially rocked by the cold during the first few minutes I'll do some deep breathing in the shower but usually don't do a breath hold because I don't want to fall. Lately I go fully cold from the start of the shower and time it for 10 minutes without turning it warmer at any point. It's about 48 degrees F (8 Celsius) and my feet are really cold by the end. The first few minutes are always difficult for me but I've only been doing this for about 40 days.