Step 1: Get your supplies out. I usually use 2-3 rolls of tape to make a purse. You need scissors, a piece of thick cardboard and either a lap desk or cutting board, stapler w/ lots of staples, and a ruler if you need.
Use the ruler and measure your favorite purse or use a piece of paper to draw the size you'd like then measure it.
Get your cutting board/lap desk and start laying out strips of duct tape at least 1-2 inches longer then your measurements. With one of the 3 rolls. (I usually use a print for this step.) Start with the strips that will be going up and down. Take the strip and turn it over sticky side up. Lift it up and fold long ways (hotdog fold -----). Smooth it out. (It might take a few tries to not get any wrinkles.) cut the strip to fit your measurements leaving a little extra (at least half an inch on each side) then cut along the long side to get any extra off.
Continue step 3 until you have The desired amount to fit your measurements. You will need enough up and down strips to cover both large sides and both small sides.(I usually do 9-11 strips for the main sides and 3 for the small sides. I always do it in odd numbers.)
Next cut the strips like in step 3 but you are cutting the ones that will be going side to side. (I usually do 7-9 strips for these. These strips aren't as important to keep odd. Also I use a solid colored tape here.) You will need enough to cover both large sides and the bottom. (I usually use 3 for the bottom).
Once all your long strips are cut take how many ever you will be using for your short sides (I usually use 3) measure a piece of duct tape that's at least 1-2 inches wider then the strips. Cut these the same was as step 3 leaving at least half an inch on either side. You will use this size for both the bottom and the small sides.
Now that all your strips are cut you are ready to start assembly. Take your 3rd color (or solid color) and measure out a piece an 1-2 longer then the long pieces. Turn it sticky side up and start placing the strips you cut for the up and down part. Only put them about half an inch onto the tape. Once all your pieces are on turn the strip back over sticky side down. Take your long strips and start doing an over under pattern. On the next strip change the pattern to under-over. Each time switching. Continue doing this until you have all your long pieces in place. You might have to pack them in there to get all in.
After all pieces are in place cut another piece of your 3rd color tape and place it on the bottom of the exposed strips. Once you do this flip the whole thing over so the sticky sides are up. Fold over the extra tape on both the top and bottom. cut off any extra on the sides that's longer then your strips. Do the same for the sides. Only cover the extra from the strips.
Continue step 8 for both main sides, small sides and the bottom.
Next take your solid color (or one of the 2 colors if you used 2 solids) and cover the back of each piece completely.
Now take your 3rd color and measure out a strip 1-2 inches longer then both short sides and the bottom all laid out flat together with the woven side face down (small side-bottom-small side). Place about half of the strip onto the 3 pieces laid out. Next flip the pieces over so that the sticky side is up. Line up one of the large sides to the bottom putting the woven side face down. Cut along the side of the large piece to the bottom. Lift up the large side and take a short side and wrap the extra around the large side. Do the same for both sides.
Do the same for the other side in step 11. Next take a piece the width of the small side and fold half on the bottom and the side. Do the same for the other side.
Once all that is done I take the color that is in the inside and cover all 4 corners then across the bottom on all 4 sides. Mostly covering up seams and preventing any sticky to be exposed.
Now take your ribbon and staple it on one side about 1-2 inches down. (I normally put about 3 staples up and down then 2 across those long ways.) Do the same for all 4 pieces of the straps. Next take your 3rd color (or whatever color you used for step 11.) and wrap it around the outer top covering the staples. Lay the straps on the sticky side and cut around them along with the corners. Fold down all extra sticky sides. The tape that's attached to the straps you need to pull it off and cut it down so just enough to cover the top is left then fold that down.
After you have finished step 14 take either the color you just used or the print if you used one and wrap it along the inside at the edge to cover the staples. Your purse is almost finished.
Last step! YAY! Take your cardboard and cut it to the size of the bottom of the purse. Rounding the corners a little helps it fit better. Wrap it in whatever color you want. ( I usually use the print or the opposite color then the inside of the purse.) Lastly place a couple of pieces of rolled tape on the bottom in a couple places then put inside the purse. There you go! Sorry this was really long but its really thorough.