I was researching how to make a base for a Warhammer model, when I found a cool tutorial by Jay from ‘Eons Of Battle’. He used carved sprue to make crystals. I thought this was a great idea. 
But, this gets better! To make a base with cracked earth and lava, he used eggshell! Like really! Who would’ve thought that eggshell could look so good! 
So I thinks to myself “yes green is fine and all, but what about red?” So I made some red necron crystals. Then I thinks “but I am working with a big base, these little crystals are just too small”. So I made some larger crystals out of hardwood!

And that is why creativity is endlessly helpful.
Jay has many more inspirational techniques on his channel (Link above).

Here is a photo of a wood crystal