I use a little portable shop-vac type deal that charges from the lighter port in my car or in the house. Not easy to find anymore but a great tool. The small oreck vac they give you when you buy a upright vac as part of the deal is good too, but I feel unprofessional using a customers power for work. Other than that I like drafting brushes. Usually made of horsehair and are narrow enough to easily get into a track. As far as brushes go I actually like to use an old sweatshirt over a small flathead or a butter knife. Gets into those corners real well. I also charge more when cleaning tracks is specifically requested as I find it to be more work when they ask about it, however I do a quick brushing of tracks and sills on every window I clean.