Phil has pretty much described the method I've used for decades with good results. The difference in our technique is after ensuring the covers sealing area is true, I clean with a degreaser then apply adhesive sealer (I prefer k&w copper coat gasket compound) to the valve cover, then place the gasket on the cover. I then apply a film of Vaseline or other release agent to the head (that's been well cleaned). Last step is a a bead of gasket maker to the bottom of the gasket that's glued to the cover. It's a lot easer to remove the gasket from the valve cover at some future date than the head. Vaseline insures easy release when future valve adjustments are performed.
Good Luck,
Ron
