Whenever I teach, I'm often amazed at the number of quilters who have trouble with the sewing machines they bring to class, right before they start to sew. Skipped stitches, thread breakage, tension problems, etc. It's always difficult to watch some of them become frustrated and struggle with their machine during class when all they really want to do is sew and get on with what everyone else in the class is doing. I cannot always stop the class so they can clean their machine and get it going before we go on to the next step. Do yourself, your teacher and your machine a favor. If you're thinking of taking a class, here are a few things you can do beforehand to make your experience pleasant and productive, not frustrating. This also goes for everyone else in general who sews, not just class takers. These things should be done on a regular basis if you quilt at all.
Number 1 - CHANGE YOUR NEEDLE. It matters, so do it often. Dull, bent or broken needles can definitely affect your sewing. If you sew frequently, then your needle goes in and out of the fabric thousands of times. I was originally taught to use an 80/12 needle, but now I go with a 75/11 or 70/10 needle. Try a finer needle. You may find that it makes your piecing much easier and your blocks will look better, particularly if you make small quilts. Some quilters go by the rule of changing the needle every time they begin a new project. That's not always practical if you're mostly making small quilts but it's still good advice to do it often.
Number 2 - Try a different thread. I can't remember now but I am grateful to the person in one of my classes many years ago who told me about using Aurifil 50 wt cotton thread. It's wonderful - thin but strong and takes up less space in the seams (so your seams lie flatter). I like a nice neutral tan for sewing with both light and dark fabrics.
Number 3 - Do your machine another big favor - take that little brush that came with it and clean out the bobbin casing and all around and underneath the plate or anywhere else you see lint. Do this often and your machine will thank you. I take off the plate and clean out the lint from around the bobbin case every time I change my bobbin. Every single time. I'm not lying. It takes me about 5-10 minutes tops and is so worth it. Before this became a habit, I would start to notice problems when I forgot so now I take the time and do it automatically when I put in a fresh bobbin. And I'm still always amazed at all the crap that accumulates in there even though I do it so often. (Tweezers help get the big clumps).
Although Aurifil thread generates much less lint you will still get lint from working with certain fabrics or batting. One time I noticed a student was having a lot of problems with her machine before class so I suggested that she clean her bobbin case to see if that made a difference. Oh my Lord - I wish I had taken a picture. It was so full of thick, smashed down lint that the bobbin could barely move. So, if you haven't looked in there and cleaned it in awhile, be brave - go clean out your bobbin case. Now. (If it looks really bad, take a picture for me!)
Oh, and make sure to keep your sewing machine manual handy in case you forget how it put it all back together!
Don't be a chicken. Just do it.
Once you've done these things, especially if it's been awhile, you'll be amazed at how much better your machine runs. Try it and tell me what happens. I'll bet sewing will be a breeze after that and you won't have to waste your precious time fussing with a machine that's crying out for some TLC. You'll have more time to make pretty things!