I am based in Jackson, MS. All of our flight plans are canned as /I, but sometimes that equipment does not even help out. That is when you need to be good at triangulation and keep track of your flight progress. I currently have a plane with just an ADF and two navs to get from place to place (this is the backup plane that no one ever wants to fly because of the equipment). It is difficult, but i can depart JAN flying direct to HOU (~300 miles) and have no problem finding it, even after they give a reroute onto the arrivals. Of course after months of flying this route you kind of get a feeling for the direction you need to go, and when it is clear you can verify your position over known lakes and towns and stuff like that. The whole point is is that we are always filed direct, and it is legal because we can get there without breaking regs.