Cleaning your machine
If you sew then eventually you will need to clean your machine. A dirty machine can lead to broken needles, annoying noises, snagged fabric and skipped stitches. Your machine should be cleaned out often but the frequency depends on how much you sew and what fabrics you sew with. If you sew often then you should clean your machine more often, about once a week if sewing with none fuzzy fabrics like cotton. If you are using felt, fur, fleece or any other fuzzy fabric, clean your machine once you finish that project.
Cleaning your machine is simple but I recommend dedicating some time to make sure you get all the dirt and lint out. To get started you will need your machine's manual to see if there are any special instructions or no-nos. If you can't find it most manufacturers have them available online for download. If your machine is older, call the manufacturer and ask them for any tips or FYIs on cleaning your machine. Next, grab a basic craft paint brush (No need to bust out your fine tipped natural bristle brushes, nylon is fine). The brush grabs the lint and dirt stuck deep inside. Take the cover off the bobbin case and the needle plate cover and brush it down. Then, take out your bobbin and your bobbin case and brush both of them down well. Remove your bobbin case (or shuttle) and brush it all over. Then take your brush and go to town on the inside of your machine, in and around where the shuttle sits and any area that you can fit your brush. If the brush can fit there then I will bet there is lint in there. Gently twist and swish your brush around and clean off the lint each time. Look for unexpected places for lint to hide: I have an auto thread cutter and the lint just builds up on it(last picture above with red circle) but you wouldn't know it because fabric is always covering the knife when I use it. So I lower my presser foot and push the button for the knife to slide out and brush it quick and continue to do so until no more lint appears on my brush. Be careful with oil, some machines need it and some don't; your manual will instruct you on this. My machine came pre-oiled and doesn't recommend that I add any. Carefully reassemble your bobbin area. If the body of your machine is dirty you can gently wash it with a natural spray cleaner like vinegar and water.
To clean your serger you will also need your manual and a small paint brush but also some machine oil. Most sergers need to be oiled on a regular basis because they move so fast and with such precision. If your machine doesn't need to be oiled you can find that info in your manual. Before you oil anything in your serger it is important to clean all the lint out otherwise lint can get stuck in the oil and gunk it up. Starting on the outside, I love to use a scrap of knit fabric and rub down the outside to clean off all the lint. The knit really attracts the dust and dirt without harming your machine. It would take forever with a brush. Next open your machine and, again, go to town with your paint brush and clean out all the lint from every nook and cranny you can find. Then, carefully add just little oil to any parts outlined in your manual. If it is hard to get the bottle to the parts, I recommend using another cheap paint brush and using it to dab on the oil.