Well . . .
Clean bobbin area often
Don't be so cheap as to used a needle until it "thunks"
It's OK not to finish something you truly don't like (last minute purchase to take to a class - like 30 minutes before class started - and I didn't like the fabric when I bought it)
Don't wait until the last minute to buy fabric for a class (see above)
Spend some time each day sewing/quilting (even if it's only 20 minutes). Don't wait for a significant amout of time for sewing, chances are something else will pop up & it could be weeks (or longer) before you'll get back into your sewing area again. Been there, done that.