Let us start with the pattern: While mine unfortunately is not commercially or anyhow available for you, there are plenty of patterns for download. This here for example, or this or that or this... So, you should get your pattern ready (download, glue together and cut out or buy and cut out or draft yourself and cut out) and some fabric. I need about 50 x 70 cm for my panties. If you'll use elastic bias tape for the hems, you'll need 1-2m for the panty (depending on size). If you hem with a twin needle, you should have that handy and two cones of yarn. Let's get started!
I cut out my fabric pieces. As you can see, in my pattern the crotch is elongated from the front piece. Make for one less seam! I started with pinning all three pieces together:
The crotch piece has to wrong side up, so the nice print ends up visible! I sewed the seam with a serger, but a tight zig zag stitch on your sewing machine will do!
Next up is the other seam to fixate the crotch piece:
Initially I folded the seam allowance under before I sewed but
- this was very fidly
- and it looks just as nice to use a zig zag stitch over the fabric border. See?
Next thing is the leg openings. For this panty I used elastic lace made for underwear. It is very stretchy which is good for blood circulation and invisible panty lines! While pinning the lace to the fabric, I fold the seam allowance under and stretch the lace slightly:
I use my sewing machine with a zig zag stitch again to sew everything together. My stitch is 3mm long and 2.5 mm wide, in case you are interested! I go once around each leg opening with the lace.
Next, I close the first side seam (in my case with a serger, otherwise just use the same zig zag stitch again! I close one seam first as this allows for prettier lace application at the waist. So remember, only close one side seam first!
While I was at it, I took a picture of how I deal with serger threads. If you just cut them straight at the end of the seam, the seam will rip sooner or later. I used a big blunt needle (actually for sewing knitted clothes together) and pull the threads back into the seam:
Next I pin and sew the lace around the waist line. Just the same as with the leg openings!
Then I close the other side seam and pull the threads into the seam. If you use zig zag, you can just use your regular back stitching to keep the seam from unraveling.
Aaaaaaand we are done! Pretty, comfortable panties in next to no time. I make mine in under 1h, but I have made several ones, so you first trial may be a little longer!