By far the easiest method that requires no special equipment and can be done anywhere. You start by picking the rose petals off the flowers, and then spreading them out on a flat surface in a dry place, that is well ventiled. When using this method, it's best to keep the petals out of direct sunlight so that the color doesn't fade. At room temperature, the petals will take anywhere from a few days to a number of weeks to dry.. Make sure they are completely dry and crispy before storing in a glass container, to avoid mold. 

I like using this method for drying whole rose flowers, that I most often use for home decor. It takes a lot longer for the flowers to be fully dry than with other methods, anywhere between 2-4 weeks. But I find that it works best for a natural look. If you dry whole flowers with the flower stems attached, you can either place them in a vase and allow them to dry or hang them upside down on a string or floral wire. This works great for dried flower arrangements. If you're only drying flower heads, make sure to place them on a porous surface (such as a basket, cardboard box or a wire rack) to prevent the flowers from molding. 

We just got a dehydrator for the first time earlier this year, and I am pretty smitten. I've used it so far to dehydrate all sorts of things, from strawberries to herbs to different flowers. But dehydrating rose petals and rose blooms is by far my favorite for one simple reason: the smell. The whole house is filled with the most pleasant rose aroma that isn't too strong and yet very pleasant. 

You simply pick the petals off the flowers, and spread them out evenly on the dehydrator trays. You then set up your dehydrator to work for around 5 hours at roughly 130F (55C). The drying process is much faster than with other methods, and you can be certain that the flowers dried in this way do not contain any more moisture and are thus safe for storage. You can also use the dehydrator to dry whole smaller flowers.

In my opinion, using a dehydrator to dry your rose petals is the best, fastest & simplest way to dry flower petals. The only downside is that a dehydrator is required. While I resisted this purchase for a long time, I am so happy I finally pulled the trigger. HERE is a similar one to mine. 

3. The Middle Route: Using a Oven

You can also use an oven to dry flowers. While I haven't done this since getting my dehydrator, I did try it in the past. You simply spread out your flower petals on a cookie sheet, turn your onto the lowest setting it will allow, and keep your flowers in there until fully dry. 

The downsides of this method are that you will not be able to use your oven for any cooking for (potentially) many hours while your flowers are drying. There is also a higher chance that the dried flowers will lose some of their color, or before over dry. 

Pressed Flowers: This is a classic method, that is also very easy & produces lovely results. Simply take a blank piece of paper and fold in half. Place your flower petals or whole flower (must be small though) on the inside, to protect your books from staining. Place the folded paper with the flower inside under a heavy book. In a few weeks, you will have a beautifully pressed flower that you can use in decorative DYIs or crafts. 

Microwave: I haven't personally tried this method, as we no longer own a microwave. However, I believe that you can dry roses in a microwave by covering them with silica gel in a microwave-safe container and heating on medium power for 2-3 minutes, checking every 30 seconds until dry. Let them cool in the gel for 24 hours, then gently remove and store in an airtight container.