There are a lot of good tips out there about improving sleep that can sometimes help. That being said, it's also worth looking at the reasons for your insomnia. Do you have too much energy? Are you restless? Will your thoughts not slow down? Are you laying up working about things coming? Is your bed not comfortable? Are you too hot or too cold? When did you last have caffeine?

Depression can make sleep incredibly hard. Sometimes I take medication to help with sleep but I don't find it to be super effective. For me, I just have to try to make a commitment to improving my sleep the best I can. And I rely heavily on caffeine when I can't get good rest.