|If you want to quickly copy a simple garment, it's easy to do using a needlepoint tracing wheel. (This wheel has longer, very sharp points, which will pierce fabric.)
Lay a piece of paper on top of a surface such as a cardboard cutting mat. Place your garment to be copied on top, and run the tracing wheel around the edges of one piece, through the seams, etc. The points will go through into the paper, marking the seam lines.
Obviously this is a quick method that will give you a 'close enough' pattern for things like nightgowns, T-shirts, PJ pants, etc., and can be very handy as a starting point for making a garment without a commercial pattern, or for copying details to add to another pattern.
You can also trace paper patterns using this technique, although I find it takes practice to be as accurate as with a pencil.
One thing I would suggest is putting the date on patterns that you make, including the year. This can help you know just which size they are, and if you do lots of traced patterns, it can help you know which one it is.