One tool used by most quilters is the rotary cutter. There are four basic sizes: 18 mm, 28 Mm, 45 mm, and 60 mm. If you are cutting fabric for intricate pieces such as circles or applique, the best cutters are 18 mm or 28 mm. The 45 mm is versatile and easier to use, allows you to cut 2 – 3 layers of fabric, and is a good size for a beginner. If you are cutting multiple layers, the 60 mm is the one to use.
I replace my blades after a couple of projects or when it starts skipping threads. Some quilters replace the blade when starting a new project.