I put the Lollypop forest together so I could work out any problems before I drag it to the office. For the base I used the top of a paper box. I drilled some holes in the top and stuck in the lollies. They were wobbly so I hot glued some foam core on the inside. This added about 3/4" to stabilize the larger pieces. Some of the holes were too large so I compensated with toothpicks.
I covered the base with "snow". I think it looks pretty good. Now I I have to take it all apart :-( to transport it.