What's the best way to wash a backpack?

Hey there, I'm curious about the best way to wash a backpack. Do you have any tips or suggestions on how to go about it? Is it better to hand wash or use a machine? Should I use any special detergents or can I just use regular soap? I'd like to keep my backpack in good shape for as long as possible, so any advice you can offer would be greatly appreciated. Thanks in advance!