I quite enjoy recording myself singing and playing guitar and it's a useful way to get feedback on my progress. I'm not after a professional recording setup, just a good way to get decent recordings.
I have a simple 2-channel mixer => USB and currently I use my acoustic guitar line-out for the guitar, and an SM58 for vocals. I'm loath to mic up the guitar but I wonder if I should consider changing my vocal mic and if so if I can do that without spending $100s. I'm aware the SM58 is a good mic but is tailored to performance so is very position/direction-sensitive - I'd rather not have to be distracted by microphone technique when I'm singing.