There are very few men who will get a tattoo here unless it is part of a much larger tattoo design that just happens to extend down to this area. So many of the common female tattoo designs can be used here. Anything from a fairy to an angel to a butterfly can all work well in the area. Often women also like to get more traditionally many tattoos in this area. Such as a skull and crossbones, a dragon or even a nautical star. However, due to the placement of the tattoo in such a sensual place it no longer looks to many but interestingly enough very sexy. The juxtaposition of a mainly tattoo is such a feminine area often works really well. Another consideration is many people like to get symmetrical tattoos in this area and might design a tattoo that worked well on both sides. For example a angel and a devil can work well with one on each side of the hip.
Whatever design you choose you will want something that is pretty small and not to large. Since the hip is a small area it will fit better if the tattoo is smaller and therefore you will want it to be not overly intricate either. IF you get a really small tattoo that is very intricate you are headed for an ink spot in the future that can become indiscernible.