What I ended up doing is disassembling one of my D-rollers to reuse the metal bar and the rubber strips on that. I'm sure you could use substitutes such as a pvc pipe or the core of a roll of paper, but I just wanted to make it as close to the specs of the d-roller as possible. Once disassembled I cut a piece of builder's paper about 28x48", laid it face down, and attached the bar to one end and the rubber strips along the sides.
The main problem with the builder's paper though I've found is that it it has a very strong curl itself, so you have to work around that. The nice thing about the material the d-roller uses is that it lays perfectly flat when its unrolled so its much easier to use.
As far as the actual technique of rolling, I would roll up the print very loosely and let it sit for about 2-3 minutes, and then rotate 180 degrees and repeat to get an evenness to both ends. One other thing I noticed is that the top and bottom edges of the paper would have a slight bump on the back side. I'm not sure what causes that but I always print some excess border on my images that is usually cut down so it isn't really a problem.