When I do wilderness travel, I sort of make it a branching maze. For example: “You are in a broad clearing. From here you can go east into the valley or you can ascend the large hill to the southwest. You could also turn around and return to the pine grove to the north, which you just left.” The players understand that I’m presenting them with choices that are likely, given the terrain. Sure, they could choose some unlikely course of action, like going halfway up a hill and then walking around, but this will be slower, pointless, and they will just end up at a recycled version of one of my established locations anyway. This gives them a bit of freedom, and makes wilderness seem less arbitrary. Some ways are faster, some can be very slow (like a valley which gets thick with vegitation once they enter) and some can have encounters.
I really like this system. It lets players move around more or less freely, but still has enough structure so that the DM can keep track of where you’re going, where you’ve been, and how long it took to get there. For difficult topography like swamps and dense jungle I make the waypoints very close together, so that many movements are needed to cover a small area. If they are traveling over wide open grasslands, I’ll make the dots very far apart. I usually space them based on time, so that traveling from one waypoint to the next takes a couple of in-game hours. When the players have gone through a few of them and I tell them the sun is setting, they will actually have a sense that in-game time has passed.
This offers a nice theoretical “wall” around your gameworld. When the players say they want to go west and leave the game area, you give them a few waypoints of increasingly difficult swamp / desert / cliffs / mountains / jungle. If they are actually roleplaying, they will have to ask themselves, “would our characters really be wading through this crap for no good reason?” If they keep going and enter the blank, empty areas of the map, they shouldn’t be surprised at the lack of towns and other interesting locations. Who would build a city in a swamp?