Neatness in pinning, patterns and fabric, is what it's all about! Patterns need to be pinned carefully so there is no distortion of the pattern. A distortion on the pattern will possibly give you an inaccurate fit. Inaccurate pinning of fabric can cause rippled and/or mess seams. So, what do we do about this ?
When pinning tissue patterns to fabric stick the pins through he tissue into the fabric with the points of the pins pointing toward the solid cutting edge of the pattern. These pins should be perpendicular to the solid cutting line. This way you can smooth the bump in the middle of the pattern piece out towards the pattern edge without having to repin!
When pinning fabric pieces together to sew, pin the pieces together with the pin heads hanging off of the edge of the fabric. This is a speed sewing technique. Again, these pins should be perpendicular to the edge of the fabric. You are now ready to sew.
Remember: Never, ever, sew over pins!!!