I have the best old-fashioned roses in my yard. Pink, with compact petals, they are super fragrant and prolific. I've taken to drying their petals every year and saving them to make rose tea.
You can pay quite a bit for "rose tea" blends in the stores. Instead, I make my own. I buy plain, loose leaf black tea and mix in the dried petals.
You can put other things in with the rose petals--here I put some cardamom pods in as well.
Drying the petals is a simple, pleasant task. I lay down a clean tea towel in a warm, dry place out of the sunlight. I pluck the petals and lay them across the towel, making sure that they are not all on top of each other so they have room to dry without molding.
Then, I just let them sit there until they are dry to the touch. I don't have air conditioning so I find that when it's a hot day, the petals will dry out indoors within a 24 hour period. You could do it outside as well, but make sure they are in a shaded, covered place. I suppose you could use a dehydrator or dry them in a very low oven as well. Just be sure to use the fragrant kind of roses, usually the heirloom or old fashioned roses. The hybrid roses we have these days are bred mostly for looks and aren't very fragrant. And of course, make sure the roses you are using haven't been sprayed with pesticides. I've found the color of the petals concentrates as they dry:
I store my dried petals in clean, recycled glass jars. Store them in a dark cupboard---light exposure will discolor them.
You could also use these in bath mixtures or salt scrubs.