M - Meter
A Meter is 100cm and if your out shopping often fabric is sold by the meter so bear that in mind when you are making your fabric list. As you become more experience sewing you will start to know your measurements, for example, I know that I need 3 Meters of fabric to make a full length dress. Some places that sell off cuts will have a Meter ruler handy so you can measure out the fabric and make sure you have enough for what you need.
N - Needle
You should regularly change your Sewing machine needle, your machine will sew better and your thread wont get caught an snap. Often if your struggling with Tension an new needle will do the trick. I change mine every 8 hours of sewing or when I finish a project.
O - Overclock Stitch
An Overclock Stitch will stop any raw edges from fraying, many sewing machine come with an overclock stitch option but if yours doesn't and you need that function you can purchase an overclocking machine. I have one and at first it was a little tricky to understand how to thread it and getting used to using it but once I did i fell in love with it.
PQR will be posted soon.