You don't need to pay their expensive prices to get brand name lingerie.
Step 1: Materials
Cotton - about 3 square inches, try to match the color of your lace, not necessary
Step 2: Cutting Lace
Crotch: cut two 8.5" pieces of lace
Step 3: Pinning Lace
Crotch: lay the 8.5" pieces out the same as the waist band (fronts facing inward). Pin the pieces together by placing the pins down the center of the lace pieces. When you are about 1.5" - 2" from the end curve the pins towards the corner of the lace. See picture for assistance
Step 4: Sewing Individual Pieces
Crotch: use serger to sew along the line of the pins. BE CAREFUL make sure you are doing this on the correct side. What ever corner the pins curve to you want to sew on that side of the pins (see image). If you don't have a serger first cut on the side of the pins you would have sewn on the serger, then use a zig-zag stitch and make sure it hangs over the edge of the lace.
The end of the crotch piece that gets wider will be on the front of the panties.
I provided images so you can see how the individual pieces turned out.
Step 5: Putting It All Together
Sew them together with your sewing machine using the zig-zag stitch. You will want to use a thread that is the same color as the lace b/c it will show up on the front of the underwear. I didn't have pink thread so I used clear thread.