Take your time...
#1 - Wear safety glasses
#2 - Practice on scrap pieces.
#3 - Use the right size/type blade for the job.
#4 - The shoe is meant to be a guide for leveling and stability. Hold the shoe tight to the pipe. Lock your arm against your body for stability. When you start to cut while keeping the shoe against the pipe, let the tool do the work. Eventually, you'll get a feel for when to apply more/less pressure. Just like welding/soldering it's always good to practice on scrap pieces to build confidence.