Lawncare is famous for a whole collection of voodoo and witchcraft solutions. However, here are a couple of things that come to mind.
If your soil doesn't drain well, you can try adding a little sand every year in the hopes of creating a "loamier" soil.
You didn't mention moss, but it is common in yards that don't get sunlight or good drainage. A healthy application of iron right now is a good idea. You will know it worked because all the moss will turn black. Don't thatch until after the moss is dead, then get as much of it out as you can.
Go buy a book or two on lawn care if I remember right, Jerry Baker writes some pretty good ones. Just keep in mind that lawns can be real sinkholes for money and sweat, and the results don't last.