I love these CocoKnits Leather Handle Kits - Simply untie and remove if you need to wash your favorite bag. These are really versatile and lightweight. No sewing or hardware required. Begetable-tanned leather, with washers and cords for a reinforced attachment to your bag. 

Includes:

:: 2 leather straps (16" x .5")
:: 4 leather washers (1" x .5")
:: 4 leather cords (2mm x 5")
:: Instructions for attaching to a bag
:: Instructions for sewing your own cloth bag (BONUS!)