Spots have never been much of a problem, but, like many women (black and white) I do suffer from greasy skin around my nose and forehead. This makes the said areas shine rather more than I'd like, and I end up looking like I've just stepped out of a chip shop. Powders do cover the problem, but it's not a long-term solution, and besides, there are some who think covering the offending pores makes them produce more oil in protest.
There are various "mattifiers" or "shine inhibitors" on the market, but not all are suitable for black skins, so before you pick one, check whether it is clay-based. If it is, don't bother, as once it has dried it will leave a white residue.
Face papers are the simplest (and cheapest) way to deal with the problem. The papers come in slim booklets and you simply tear off a page and use it to blot the excess oil from your skin. Although convenient, the texture is similar to greaseproof paper, which isn't exactly pleasant against your skin. And be prepared for a nasty surprise when you see just how much oil comes off on to them. Another word of warning: steer clear of The Body Shop papers because these are powdered - a good idea in theory, but not ideal for black skins, as the powder is beige. The Shu Uemura face papers are the most effective, but even these felt like wiping my face with very cheap toilet paper (or at best expensive tracing paper).
The best, and most long-term, way to reduce shine is to treat the problem of excess oil, rather than just mopping up the symptom. The Decléor T Zone Regulateur made my skin look and feel less greasy almost immediately, without leaving a nasty residue. As did Mat Specialist, from Helena Rubinstein, although this fluid felt quite heavy. For a cheaper, but equally effective, version, try The Body Shop's Tea Tree Oil Anti-shine Lotion. But their gel Mattifier is best avoided. Although clear, it is far too sticky (as is Marks & Spencer's Revival shine inhibitor) and doesn't work well under make-up. The best of the bunch is Mat Express, from Clarins. Leaving the skin elegantly matt, this clear gel is a great base for make-up and even works well as an alternative to powder.