Not quite settled on the interior yet, but I think it will be light colors. Maybe white and gold?
No need to heat the punch. I take a little out of the inside of the tube with the point of the blade, then cut to length.
After that I stand the stubby on end and tap the tool with a light hammer. I only had one that split, but I did hit it to hard!
I used 3/32" tube, it's a little bigger than the metal stacks I have seen and that is the look I wanted. You could use any size.