You can make a rosary out of any amount of beads that you want. Whether it's 108, 111, 88, 216, etc. etc., all of those are fine. It depends mostly on what kind of energies you will be working with numerologically speaking. When in doubt, 108 and 111 are always useable.
Just take the number of beads that you want and put them all on a string, then tie it nicely together and you are done. For a simple rosary you don't need affirmation beads or anything like this. A 108 bead rosary simply has 108 beads tied on a string.