Clean, dry fabric! Cut the fabric in half from selvage to selvage. This leaves two half-yard lengths. Layer them, right sides facing together. If your fabric is slightly skewed (not at 90 degree angles in the corners) grab opposite corners and pull the fabric until it is square. This prevents your clothes from hanging crookedly later on.
Now measure out your (hip measurement)/2 + 13" (red) and cut off the excess
I made an industry standard size M, so it is 38"/2 + 13" = 19" + 13" = 32"
The 13" is extra room so the bloomers are not super tight when worn! Really you can add however much you want
The blue side is just 1/2 yard for the purpose of this tutorial, but in the future you can make it longer or shorter as you please
Now cut out your crotch curves! The shallow curve goes in the front, and the deeper curve goes in the back (for your booty!)
The depth from waistband to crotch is up to you, depending on where you want it to sit (waist, hips, etc.)
Overlock or zigzag all the way around to prevent fraying
At this point, you should make sure you have one left and one right side. If you ended up with two of one leg, it means that you did not lay the two fabric pieces right sides touching! I have committed this crime before...
Now, fold each piece right-side together,sew up the inseams (the straight area below the crotch curve) on your sewing machine and you should end up with two tube-y legs like this
Turn one leg right side out
Place the right side out leg inside the inside out leg
Here is a close-up to show what I mean better. Stitch up the U-shaped crotch curve. Make sure you pin the intersection of the inseams before sewing! It is very important to always match your intersections. Not only is it a sign of professionalism, but in areas such as the crotch or underarm, if the intersection is not matched the garment will move strangely and pull incorrectly
Now you should have a pair of very big pants. Time for elastic!
Fold up 1/2" at each leg opening and the waistband, press, and pin. I used 1/2" because my elastic is 1/4" so I will be sewing at 3/8", leaving enough room for elastic. Adjust your seam allowance according to your elastic width
Sew all around, leaving an opening for threading your elastic
Measure out how much elastic you need for each leg and the waistband (remember, it should be a little bit less than your leg/waist measurement so it will stretch a little and stay up)
Stick a safety pin through it and feed it through the channel. Secure the ends of the elastic together with a zigzag stitch (go back and forth a few times), pull it all into the casing, and sew up the hole