Sewing Techniques and Stitches.
This tutorial on How to Install an Invisible Zip is really handy if you are working with zips and gives some brilliant tips. Follow the link for the tutorial; http://gotosew.com/2015/07/how-to-install-an-invisible-zipper/
If you would like to learn or brush up on other basic sewing skills and techniques go here; Sewing Techniques & Stitches to find the skill you would like to work on.
If you would like to see easy/ beginner sewing projects go here; Easy/Beginner Projects
If you would like to see challenging/Experienced projects sewing go here; Challenging/Experienced Projects