One of my favorite kimono rentals in Arashiyama is Kyolan Kimono Rental. It has one of the best locations, a relatively large collection of kimonos to choose from, and a spacious interior (compared to others). The staff is also very friendly.

Check out their website (available in English) for different options. I highly recommend booking in advance, especially during peak seasons, as the store can get very busy and you may not be able to get a kimono.

The whole process is really simple: you choose a kimono, then one of the professional staff members helps you put it on, you choose shoes and accessories, leave some of your belongings there, go for a walk, and come back in time.