To begin, you will want to look at the manual for the sewing machine you are using. If you don't have a manual, I'm sure you can google your machine's model number and find a PDF version of the manual online. If not, you can do some research on the Internet. Youtube has some great videos showing the basics. I just popped over to Singer (my machines) and see that I can download any of them. While you're at it, you might want to pick up some sewing machine oil. Be sure it's for sewing machines. You can get this anywhere you can buy sewing supplies.
How often should you clean it? I've seen some articles saying after every project. Well, that can be confusing because I may do one project that requires seven or eight hours of stitching time, or I might throw a mug rug together can be done in about an hour. It really depends on how often you use your machine.
Is your machine a workhorse?
Do you do assembly line sewing?
Do you crank out a bunch of potholders for craft shows?
In the above cases, you're going to want to clean it at least once a day.
Are you an occasional sewer?
Only sew once in a while?
For these stitchers, you might want to clean after each project so you don't lose track of when you did it last.
I personally sew often, but my machine isn't what I'd call a workhorse, so I make sure to clean and oil my machine once or twice a month.
My Personal Tips: Now you know the importance and basics, and have read your manual or researched your machine, so you know what to do. I'm now going to share some of my own tips with you.
1. Fresh oil is a must. If you aren't sure how long your oil has been sitting in your cabinet, or your oil has turned yellow or another funny color, toss it and buy another one. Old and dirty oil will not be good for your machine. It's not that expensive to replace.
2. When removing or replacing the throat plate, be careful with those screws to make sure they don't fall into the machine.
3. Never blow into the machine to remove dust and lint. You can actually send the gunk to places you don't want it. You can use a small vacuum and remove it that way if you want.
4. I'm not a fan of that small and stiff brush that comes with the machine. I use a soft makeup brush that I bought just for this purpose. The lint seems to attract to it like a magnet, and since it's so soft, you can really get a nice cleaning job.
5. Now is a good time to discard the old needle so you can start your next project with a fresh one.
6. I always run some old fabric through the machine as if I were sewing (without thread) to run the oil through.
7. Now that your machine is nice and clean on the inside, make sure you wipe off the outside and keep it covered until next time you use it.