Map making is one of those things that some GMs live for. The hours of painstaking detail to convey the lush world they're created.
There are other people however who feel that maps hinder their creative thinking. Because once it's on a map their world no longer makes sense.
I tend to take a map of a real place and file off the serial numbers as we say. My most recent fantasy campaigns I have been using my own version of Europe circa 1910. I downloaded a few maps from the interwebz and broke out GIMP and made some changes and BAM! My own fantasy world.
You can do the same sort of thing. One suggestion I've heard is to take a map of a place and then change the orientation of the map so it's not as easily recognizable as that place. The nice thing about using a real map is that the mountains and rivers and cities are already there. You can use them or not, but the complicated elements of geography are already present.
But you don't really need all that complicated detail, yet you still need to have a general map so you can convey general ideas about location, proximity, etc. to your players. Break out the spreadsheet.
For a recent game a friend was GMing I needed to sort out my character background, which involved me trekking from my home country East to the ocean, then South and finally West to the far coast. He had given a description of how the countries were in relation to one another, and the main mountain ranges and rivers. So I just marked it out in a spreadsheet. I didn't get really fancy, the continent is a rectangle with a bunch of squares and rectangles color coded and labeled. I sent it to him for review, he clarified a few things, and now it's effectively the official map of the world for the game.
Maps can be useful because some people are just visual. They need to see things to understand them. A map doesn't have to be detailed to be able to convey what the players need to know. Sometimes colored blocks will do just fine.
What are your favorite ways to handle maps in your games? Let me know in the comments.