If you're talking about a cutting pattern I'll put the pattern on the leather and use a scratch awl to trace the pattern. If I'm going to use the pattern a few times I'll glue the paper to chipboard so it can withstand more use.
If you're talking about a tooling pattern I use vellum paper and a stylus. You can draw directly on it, use a ink jet, or laser jet printer. Unlike regular paper it can take a little more abuse and doesn't fall apart as easily. It can also withstand getting a little damp. I did the tape thing for a little while but it took more time and waste than just buying the vellum paper. I paid $10 for 180 sheets.