I think felted bags are great, but if you want it to be done in a short amount of time remember they take a while to dry!
I LOVE making this Sophie bag from MagKnits
It is relativly easy. I only use a skein of Paton Classic Merino, but my sister has made this and used a bit more than one skein. She knits a bit more loosely than I do. My only suggestion on the pattern is to skip the icord handles and make one more sturdy handle.... although the twisted icord looks so cute.
Or, if you are willing to buy a book... one skein has some great patterns that don't take long for both felted bag and accessories.