One thing I have been toying with for diorama's, or at least "meant to be viewed from one intended angle", is using forced perspective to create an illusion of depth using various scales for models
For example a Bandai 1/48 X-Wing in the front, a Bandai 1/72 X-Wing right next to it and the Bandai Death Star Tiles (some really small scale like 1/350 or so). Possibly even add a 1/144 one as well.
The whole thing would not be very deep for a shelf or cabinet type of display, but gives the appearance of being so. You just have to get the lighting right to avoid unwanted shadows that could ruin the illusion
The two x-wings in this picture are nearly touching wing tips
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Another one I really want to try is a dive bomber in the foreground and a ship sideways mounted on the wall similar to this 1/72 SBD and a 1/700 carrier
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or a takeoff point of view like this [ATTACH=full]147551[/ATTACH]