At Lowes or similar places you can buy packages of cedar shakes used for roofing. These come shaped from about 1/4 inch thin down to a 1/16 inch point. These are great for gently bringing track down from a grade or starting track up a grade. The shakes are usually 5-6 inches wide so you cut them to your track width. They can be real problem solvers in many situations. They can be glued or screwed. Very useful!