For oily skin, my first recomendation would that you to invest in a good skin care range that matifies your skin and allows for better application once you have completed your regime. If your moisturiser has too much oil in it, combined with your skin’s natural oils, it will make your make-up run off. As far as primers are concerned, you might have an problem finding one that suits your skin on its own. Most contain illuminators to enhance your foundation, so rather try a powder over your foundation to help it set better. The only matifying primer I’ve come across is the blackUp Matifying Base, which works magic in terms of getting skin to stay soft and matte all day long.