I limit myself to two on separate machines at once. Just stay with them until they are done. Watch the calendar to keep an idea of what needs to be done first. If you don't do 4 Halloween ones tihs year, they fabric won't spoil.
Jeanne, your quilts are very nice. If you haven't chosen your nieces's fabrics yet, find an adorable baby fabric for the feature. Everyone will oh and ah over that. You can do it. I'm doing a log cabin style only the logs are all on two sides with a 5 1/2 feature fabric for the start. It's a cute pattern, though I messed it up adding an extra strip, but only I and my oldest daughter will notice. As Nike says, just do it.