A zester is a great tool for peeling only the exocarp (outside layer of the lemon's skin), and comes with several sizes. See Making and Freezing Lemon Juice, below. Placing the portions in a glass mason jar, rather than a plastic bag, will ensure that the small portions are not crushed or crumbled in the freezer.

Summary:
Using a citrus zester, shave off lemon peel from lemon. Use lemon fruit for juice and piths for pectin. Place lemon zest in a glass mason jar and freeze.