This kite is adapted from King of Random's Plastic Tablecover Parachutes. I made this much bigger than his, and I use heavy duty trash bags instead of table cloths. The edges are reinforced with duct tape as well.

You will need:

A large empty room or field
A scissors or utility knife
2 large size heavy duty trash bags
A roll of duct tape
About 30 feet heavy duty string or paracord
a 1.5 foot long steering bar, made of wood, metal tubing, or PVC pipe

Step 1: Prepare the Trash Bags

lay the first trash bag flat on the ground and use a scissors or utility knife to remove three of the edges, leaving one of the longer edges intact. Unfold the bag and spread it out. cut 5" by 5" squares out of two adjoining corners along one long edge, as seen in the pictures. Repeat this step with the second trash bag.

Step 2: Tape the Corners

Take a 5" piece of duct tape and put it on one edge of each of the square gaps. Fold the other edge of the same square around and stick it onto the tape. Take a second piece of duct tape and put it on the back of the joint. Repeat with the other three corners.

Step 3: Duct Tape Border

Cut duct tape pieces the lengths of the three stretches that connect to modified corners. you can cut them down the middle to save duct tape. Repeat with the other garbage bag. Overlap the untaped edges of the two garbage bags and connect them with a piece of duct tape on either side, as shown in the pictures.

Step 4: The Corner Cords

Cut two holes in each of the corner pieces of tape. Tie the end of a 3' string through each of the holes. Duct tape over the knots on either side.

Step 5: Connect the String

Tie the strings from the adjacent short edges together. This may sound confusing so look at the pictures above.

Step 6: The Steering Bar

Take your steering bar and add duct tape handle grips about 2" from the edge. Tie 5' stretches of cord at the intersection of the shorter chords. Tie the ends of the 5' cords to the steering bar an inch from each edge. You are finished!

Step 7: Conclusion

This Parachute can be used to parachute toys and small rockets. I have doubled the size of this in the past, using 4 garbage bags, and even 6 at one point. At this size it can be used as a sail for a kayak or skateboard. You can also just use it as a kite, but if it is 4+ trash bags and a windy day, you have to be careful because the force of the wind can tear it apart. You can chose to leave out the steering bar and just tie the 5' cords together.