The Basics

You're probably not getting much of a reply because your question is pretty broad.

Do you have a sketch of what you'd like to do? Maybe a picture you've seen? Even a more detailed descriptionof waht you want to portray would elicit more information.

As it stands, your question is similar to asking how to get to San Francisco without knowing where you are or what type of transportaion you want to use.

Well I was thinking it would be a battle scene with lots of trees exploding! What material should I use for the exploding trees? Also I was thinking of adding an American Tank. Do you think that would detract the fact that it's supposed to be a King Tiger diorama?

For the most part, tanks fight at distances in the hundred if noth thousands of yards, not really practical in a dio. The trouble with explosions (and fire and smoke) is they are ephemeral, lasting only fragments of a second and leave a lot of stuff suspended in the air.the expansio of gases/shockwave also affects things around them in specific manners, bending and more breaking/suspended stuff. In the 27 years I've been attending shows, judging and hanging out on line, I can count only a few really effective action dioramas, and none of them attempted actual explosions.

About the only way you might do this effectively would be by creating a boxed diorama where you control the lighting and directio of view. That would allow you to implant an LED into the explosion and support the upper part of the tree.

Here are a couple pictures of explossive type action that were on display at World Expo in 2005: