You can use Rhinestones in a couple of different ways.
You can embed them into the arcylic, I push it into the acrylic just a tad then seal it with clear acrylic..and buff the nail carefully after it is finished...........
Place them on top of the finished nail, apply a clear coating of enamel, pop the stone on and seal with sealant.
Apply a tiny bit of adhesive and place the stone on that, then you dont have to seal it and it becomes more raised and prominent.........
Try it out and see which method you prefere ....
I love the encasing in acrylic method..............
HTH