I just received my copy of The Total Tote Bag Book by Joyce Aiken and Jean Ray Laury. This is a really great resource that talks about construction for all types of bags and some design ideas, although they are from the 70s! Nothing that can't be updated, of course!
I was thinking about what I like in a bag and the most important feature for me is a long strap. For my prototype, I made the straps 28 inches long. I have a purse from H&M that I like, except for the short strap. It is always falling off my shoulder because of the coats I wear. So, a long strap is a must.
Another feature I like is different compartments. If a bag is on big space, it is a bit difficult to find things. Of course a one-compartment bag is great for toting items such as groceries home from the store or towels to the beach.
What do you like in a bag? Tell me!