of how much will come out with the amount of pressure that you use on a piece of scrap cardboard. you will likely need less pressure than you think to get a nice, even bead.
the biggest trick, besides how much you let out, is the speed that you go. your impulse will likely be to move quickly but going slower with consistent movements will give you the best finish.
when you feel like you have the speed and amount down, it’s time to get started on the surface. you will want to hold the gun at an angle to help you get it into the crack the best. although the impulse 