Okay here ya go ladies!
First, start with a pair of denim and your fabrics, make sure that both have been washed!!
turn jeans inside out and open seam. you can either leave the hem intact (which is harder IMO) or cut the seam off and let the bottoms fray.
turn jeans right side out and sew on a patch,
continue arranging and sewing until you have the legs covered as you like, I like to have a tentative pattern so I arrange them all and then lay on the table in that pattern. make sense?
now all the patches are sewn....
tun the jeans inside out again and pin the leg closed, make sure to line up carefully! sew the leg shut with a straight line.
trim off any excess fabric
serge or sew a zig-zag (if you don't have a serger) to close the leg and prevent unraveling
tada! done....
I like to embellish the back pockets a bit too, either a few deco patches or in this case ribbon and a bow to compliment the stripe fabric I used....
Hope that this helps you all. Let me know if you have questions or need anymore info!