I love 3D terrain, with fully painted armies and a nice battlemat it just looks the coolest!
I’m really liking the idea for elevated hills mentioned, this thread is full of great ideas. My first removable forest is nearly done, then I think I’ll work on a hill… 
I suppose you could have both?
Have the 3D terrain and a 2D top down picture of it, with the exact same base dimensions, sitting underneath. So when your unit moves into the 3D terrain, you lift it off the table and the 2D pic is underneath.
Same. I even arrange trees around the unit in the wood, to keep the look as much as possible. 
Magnets are a good idea, never occurred to me to do that kind of thing with a humble fence.
Hills are indeed a pain.
I find that either a flat thing the right thickness and then steps to hold units up or a gentle slope are best.
I went in between those and I sure an glad to see others have hills that are less than 1.5" tall.
Made mine from layers of cork (1/4" to be just over 1"). Making steps so the all but horribly top heavy units can stand on them because the height difference is spread out.
Warping was a pain though.
Thats the spirit! Why bother with pesky terrain?!
Perfect solution really. Or perhaps not perfect but as good as I can imagine!
This.
I’ve been in too many battles fighting “grey” armies on “this shoebox is actually a hill” terrain. Facing a fully painted army on a 3d battlefield with elevated terrain is really so much better.
From that perspective, I’d rather have the trouble of shuffling terrain around than playing again on the hills-of-adidas.
This is an example of what I use. The hill is an ancient Geo-Hex/Gamescape hill from the 90’s. The pond is a 2D neoprene mat from Broken Egg, and they also sell MDF cut to the same shape as their flat pieces , so my wife and I built it up and painted it. The final neoprene bit on the right there is from Monster Fight Club. It’s double sided and it came with rocks and tree stumps etc for you to put on for difficult terrain, but can just slide off when you have a unit in it.
Magnetized obstacles is a great idea, I may have to try and convert some of our obstacles.
This isn’t going to move the discussion on much but:
Some of my best war gaming memories are from when I first started on pretty poor tables. We were struggling to put together armies, let alone full sets of terrain.
The first set of decent terrain I picked up has been some of the best money I’ve ever spent.
I recall breaking stems off my mother’s plants in her garden and taking the smaller landscaping rocks for my boards. Fun till I got caught, hehe.
Now THATS what a game of KoW should look like! None of this pesky 3d terrain or miniatures!
