The second chakra is the sacral chakra. When in proper condition it should be seen as red. As an energy center within the body it will be effected by things that effect the body. Whatever is good for that portion of the body will be of help. Being an energy center on more than one level, which means mental and spiritual as well, anything that will promote well being in these areas will also help. More specifically, things you might try ... A warm bath with rose petals, meditation with visualization of the chakra changing naturally to red (start with what ever colour comes to mind when you do this and visualize it becoming red), and couple deep breathing with this last one.