Sewing is the bomb! I like to say that sewing (+ modification and mending) is one of the most empowering skills I've ever acquired. My mom taught me to sew when I was a teen. For a while I sewed a bunch of my own clothes, and I still sew "makes" entirely from scratch sometimes. But a lot of what I do—what I love to do—is go to the thrift store, find stuff in awesome fabrics that's /almost/ perfect... then go home and make it perfect! Making hemlines shorter, taking in the wideness of a dress—all awesome, pretty easy mods. And you might be surprised what nice things have been discarded because they were missing one button! Alteration/modification is the bomb. My one caveat is in the thrift store I like to think about how /hard/ it will be to modify something; and think if I really want to buy a project.
At first I wasn't going to weigh in, but I decided I have a nugget worth sharing. And it's this:
Drafting from nothing can be pretty frustrating. Satisfying, worthwhile... frustrating. Especially when you consider you already have tons of patterns you love hanging in your closet. (Probably.) So instead of drafting from scratch, which is a process that includes making muslins to test and get things right, which is a long and fiddly process, I love to copy clothes I already know and love. You can get creative with fabrics and get more out of a style that's your favorite!
Someday, I will make my own sloper and draft off that. But in the meantime, I've got a tanktop I've been meaning to copy!
My advice, as a random stranger on the internet, is to start by modifying/mending secondhand clothes and building the sewing skills and confidence that will make you want to draft from existing clothes, or from scratch!