On sheet goods, I've made a set of crossbars that go across the back of my truck. I lay out and cut sheets directly on the truck using a shop made straight edge. I generaly try to leave a factory edge on each piece. I have a store employee load the sheets on my truck, so I don't have to lift any really heavy stuff anymore. Making the cuts square isn't quite as much of a problem if you leave a factory edge to work from. I also use an 18 v DeWalt saw, which is light weight and is easier to hold on track than a larger saw. The 18v DeWalt tools are one purchase I do NOT regret.
The more I do, the less I accomplish.