Now you're ready to actually start needle felting. If you have a needle felting tool like the one shown, unlock the sleeve. If you have a single needle, it's already ready to go.
Though it's pretty obvious, it's worth mentioning that both kinds of needle felting needles are extremely sharp and can do a lot of damage to you and/or your tabletop if not used properly. That's why you should always work with a brush or piece of foam under your work, and you can take the added measure of covering the table if you like as well.
To protect your fingers, keep them out of the way of the needles at all times, and always make sure you lock your needle felting tool if you're going to store it or leave it unattended.
The best approach for needle felting is a straight up and down motion with the needle. Try to go in as straight as possible; this makes it less likely you'll break the needle.
Start at one end of your line or shape and work your way around. If needle felting a large shape or using the cookie cutter method, start by needle felting around the outside of the shape and work your way in.