Which foundation?

I have quite awkward skin, mostly oily and I usually get spots which I try to cover. I've used Mac studio fix which I find doesn't help the oiliness of my skin, I'm constantly powdering to reduce the shine. I have also used the pro long wear from Mac which is also quite good. Both give quite good coverage but has to be built up.

My friend uses bobbi brown foundation which seems to give a great coverage but some online reviews have put me off. Does anyone have any advice?!

I haven't used Bobbi Brown foundation but have used Laura Mercier and other higher end brands and they are all pretty good. Have you tried BB creams? Dr. Jart (any of the korean brands, Memebox has some on their site) as well as Dior are great. Some of them have a good coverage and are great for evening out the skin. I like to use powder on top and the result is a flawless finish. Unfortunately the coverage doesn't last all day but is easy to touch up later in the day with powder. Estee Lauder double wear foundation is great too and longer lasting. 

If you have oily skin I would suggest trying a matte foundation. There are a lot out on the market of course. I have heard very good things about the Loreal Paris Pro Matte Foundation- this is a drugstore one. Not sure what your price point is. I have not personally tried this myself yet. This is going to be the next foundation I do try though!