Starting out with a saw - I make all crosscuts to a knife line. That provides a "ledge" for the saw plate to ride along. For ripcuts, I take a small "chip" out of the end for starters. Jim Tolpin provided a handy tip for rip cutting: make two parallel lines to follow, that way you can see if you're wandering. Lastly, there's no substitute for practice - it took me nearly 100 feet of ripcuts before I backed off and let the saw do more work. Pressing harder into any cut lead to rough results.
