The best way is to use a fabric glue. You can go to a Michaels craft store or Joann Fabrics or any other fabric stores you have in your area. Just make sure the glue says its made for fabric and is flexible. When you hem the articles turn them inside out and then after you measure and appy the glue use something like duc tape to hold the hem up until it dries. If you use clamps or clothspins they may make a indentation in your leather that won't go away. You can also put wax paper or parchment paper over the hem and then lay a book on top until the hems dry. The paper is so the book doesn't stick to your pants if any glue seeps out.
Thanks Mary, I didn't know that fabric glue could also glue leather. I will have to try and get some. :-)
Let me know how it turns out :-)
I haven't been able to find Ailene's washable and translucent fabric glue. Neither Walmart nor JoAnn's had it, so I'll have to keep searching. Will post it once I have them shortened. And it stays up. :-)
Have you seen any other fabric glue? Since you're hemming leather it doesn't have to be washable or transluent, just flexable.