I have an old house and there are ungrounded outlets set in the baseboards. I am currently working on rewiring them and was wondering what the best way to tie the ground wires to each other and the ground screw is. From looking online, it seems to be using a pig tail, but these boxes are very shallow and I don't think I can fit a deeper one in there. So are there any safe alternatives?
I would use a crimp sleeve to save space. Hold the ends of the ground wires together side by side so that one's about an inch longer than the other and crimp the sleeve on at the end of the shorter wire. Loop the end, land it on the ground terminal, and you're all set.
Follow the instructions on the package of the crimp sleeves. Most people use linemans pliers with a crimp lug to crimp sleeves.