Even if you don’t use your sewing machine on a regular basis that doesn’t mean you don’t have to keep it maintained. Self lubricating machines need to be run at least once a month to keep things lubricated.
If you have a machine that is updatable, be sure to always have the latest update. It will not only keep your machine in good running order but it may give you some new stitches or special features.
Never use your mouth to blow into your sewing machine to clear out fuzz. The moisture from your mouth is not good for the components. Use canned air or an appropriate duster or brush.