According to your anatomy and preference, you decide the waist height, crotch width, and leg opening. Finish the waistline and leg openings with lace elastic, FOE, or fabric bands. Make your hipsters in jersey fabric. These are the comfiest underwear!
You are new to sewing. You have tried or want to try using fold-over elastic or lace elastic.
Make your hipsters with a 20-30% 4-way stretch jersey. The thickness of the material will affect the final fit. Size down with thinner material.
You can finish the edges with elastic lace, FOE, or fabric bands.