A simple homemade tire shine is pure castor oil. Castor oil is a natural product that is readily available at drugstores and department stores. It is gentle and shines tires without degrading the rubber.
Tires need to be cleaned thoroughly before applying any shine product, whether commercial or homemade. This removes dirt to give a better shine and helps tires last longer. A solution of warm water and a little liquid dish detergent cleans tires gently. A firm-bristled brush gets into the tread and removes stubborn bits of gravel.
After washing, it is important to remove any detergent residue. Detergent has a dull appearance and will keep the castor oil from penetrating the rubber. A cloth wet with rubbing alcohol quickly removes the residue of dish detergent. The alcohol dries fast to prepare the tires for the homemade shine.
Castor oil is a thick oil that shines and seals making it ideal for use on tires. A smooth cloth works best with the oil. Terry cloth or other rough fabric leaves lint on the tires. The castor oil is poured onto the cloth and then rubbed into the tire. It doesn't take a lot of oil to shine and seal the tire. One bottle works for many shines.