You can sew them but hot glueing them is the quickest and easiest for me. I love my hot glue gun and use it for everything!
I found these patterns on Pinterest. They're easy to follow and I'm happy to promote others blogs especially when I use them for my creations! I hope you have as much fun as I did making these! Ill post the links I used below. The "mothers day corsage" took a lot more time than the others, just a warning. But it turns out so cute I'll definitely be making more of those in the future.
You can put an alligator clip on the back or a flat pin to put on your shirt, belt, or bag.