Here's a quickie example of using the geomorphs I've posted with this blog and those available at Stonewerks, Risus Monkey and A Character for Every Game.
This isn't going to be a complex step by step just an overview.
I selected geomorphs from all 4 sources that I felt could flow together well enough and slapped them down together in a paint program. I rescaled them to fit together and rotated the tiles till I got an arrangement I liked.
From there I joined some sections with connecting corridors that I drew in with the paint program.
And then I finished it up. I added in another 5x5 section to the right hand side of the map because that connecting corridor was looking rather boring. I erased or added in a few staircases and entrance markers along with cleaning up a few other spots here and there. A background was added to make things flow a bit more visually (I wouldn't always bother with that last bit).Then I added in numbers to key this dungeon level set up with geomorphs drawn up by four different folks giving a lot more organic looking dungeon then I may have come up with as quickly on my own.