Did hexes are not lockable so we highly recommend creating a wooden frame that fits around your intended gaming area. This should be tight enough to hold all hexes in place during gaming, but leaving sufficient slack to allow removal and change during play.
We have found that 2mm in a metre length is sufficient for our needs but each gamer will find his/her own standard.
We have also found that having it level with the gaming surface is the best way forward, although some may wish to have a raised lip to prevent dice leaving the area.
The original concept of our hexes was to exploit the depth involved, so many of our pieces do just that.
In some cases our designs can be of more than one use. For example, deep streams make perfectly good sunken roads or tracks, perhaps even wadis if you are playing a desert scenario.
However, we expanded our remit and started going up as well, creating high ground, ruins, bunkers et al.
We also created the opportunity to display damage by substituting shell hole damage into your layout. The range is not exhaustive but we hope there are sufficient.
If your rules permit, we have included foxholes and infantry holes, which could be introduced into the gaming area during the battle itself.