I know that there are a lot of tutorials for this out there, and they are all amazing, but I just wanted to share how I did it. And since, you're here all ready...
First cut out a piece of felt, rough 4 inches square.
Then draw a spiral starting in the middle of your square. It doesn’t have to be perfect, I actually found that the less OCD I was, the better it looked. (I would suggest not using a blue marker though.) Smaller space between the lines of the spiral will give you a shorter denser rose, larger gaps will give you a taller thinner rose.
I found leaving the middle of the spiral round gives you and handy flap that helps a lot when gluing everything together.
Then roll up the spiral starting from the outside and rolling in towards your center flap. It doesn’t really matter how you roll it, I like mine a little messier, the roses came out looking fuller and more natural, but it you want to line up the ends it will look more uniform and neat with the rose petals tighter together.
This is where the flap from the center of the spiral comes into play. Don’t roll the last ring of the circle, and place a dollop of hot glue on the underside of the rose, then press the flap into the hot glue. This holds everything together better and also gives you a flat surface on the bottom of the rose which makes gluing it on easier.
On a side note, if you haven’t heard of the magic of a low temp hot glue gun, I cannot praise them enough. My mom has several for her classroom and I fell in love the first time I stuck my finger in the hot glue (which was in the first few seconds of the project) I panicked and tried desperately to get the hot glue off my finger before I burnt myself and failed around for almost a minute before I realized that I actually had not burnt my finger. I had just stuck my finger in hot glue, and it didn’t hurt. This opened a whole new world to me! (I still wouldn’t advise touching the metal tip, I found out by accident that in fact is still very hot.) So if you are accident prone, like me, I would definitely advise a low temp hot glue gun. Martha Stewart makes a very decently priced one that has switch so that it can use both low and high temp sticks depending on what you are working on.
Ta-Da! An easy peasy felt rosette!