I've done it. Its fun, and you learn a lot about all stages in the process of making an album interact. I really enjoy playing in bands, but the freedom of these solo projects is
.
The best thing to give your compositions, playing, mixing and mastering an "objective" judgement is
time:
Record all your sketches of new songs on a cassette/minidisc etc.
Don't listen to these songs for a couple of months. Same goes for performance, mixing and mastering. If you have the time to refresh your ears between these stages, the lack of bandmates/producers to bounce off your ideas is somehow compensated.