(Note: If you are a cis woman, taking more estrogen will not give you more booba, although it could possibly give you reproductive system cancer if your levels are too high)
Producing Transdermal Estrogen: A Do-It-Yourself Guide
This guide describes how a small collective produced and distributed transdermal estrogen using reproducible do-it-yourself methods.
Estrogen isn’t a controlled substance so it’s easier to get than testosterone. As far as I am aware DIY estrogen is a lot more common because of the legal risks associated with testosterone.