Right After I finish a project that did NOT use a #12 needle, I remove the needle I used and decide whether or not it is worth saving. If it can be reused I stick the needle in the correct part of a special "tomato" pin custion that has each section numbered with a different needle size. I then put a # 12 needle back in the machine since 90% of my sewing is done with this size.( Or in a pinch I don't replace it at all). I also divided the top and bottom sections of the pin cushion and put the sharps above that line and the ball points below it. I always know I have a number 12 needle in the machine'