Fold the fabric so that you have two layers and use the pattern to mark for your cuts.

After cutting, you should end up with something like this.

Next, trace your pattern onto the interfacing. Make another line approximately 3/8" inside the pattern line. This is the line you'll cut.

We make the interfacing smaller so that it will fit inside the sleeve once the edges have been sewn.

With the "good" sides facing in, sew around both of the long edges and one of the short edges making a sleeve for the interfacing.

Turn about 2" of the sleeve "right" side out and slide in the interfacing.

Continue turning the sleeve right side out, pulling it around the interfacing.

Turn under the ends of the fabric that are on the open end of the sleeve. Edge stitch the outside of the open end of the sleeve to sew it closed. Continue around the rest of the sleeve.

Sew two pieces of velcro to the outside of one end of the sleeve. Use the "hook" side here.

You want to make sure that you sew the hook side of the velcro so that it's facing away from the scrotum when wearing the parachute. The hook side is very rough and could do some damage to the tender bits.

Sew the "loop" side of velcro pieces to the inside of the other end of the sleeve.

Here's what you should have so far.

Cut the nylon webbing into three pieces each about three inches in length.

Fold the edges under and sew them to the sleeve in approximately the positions shown in the image.

Here's a shot of the finished parachute.

Here's another view from the other side.