I have a big roll of leather ready to make my (laptop) bag. I keep putting it off though because I can't settle on the design... and now I'm wondering again how I would incorporate padding at the bottom of the laptop compartment.

Has anyone else here made their own backpack like that and stumbled into issues and considerations they didn't expect?

Haven't done a backpack, but I do have a couple of leather laptop sleeves for the M#Airs. One is from scrap napa furniture leather (1mm chrome tanned), so it's soft and colorful, but doesn't protect as well. The other is ~2mm natural + pull up leather, so a bunch stiffer, to the point of being difficult to get the laptop in the first few times it was used.

Both of these sleeves are vertical envelope style, with a tucked tongue closure, and they're generally carried in some other backpack/bag. So these are basically the padding. They replaced _really_ low budget bubble wrap envelope laptop sleeves.

What I'd say from observation of the crafting/development process is that you're going to do one to figure out the issues and one to fix them all. (Or more, having seen a bunch of shoes made in my dining room)