I have a material that I want to use for my small heart boxes (1 1/2" on a side) This is a very rough material (Manzanita root, grape root) that is not square in any shape.

What would be your go to method to square up the cubes?

I have a tablesaw, small bandsaw, and stationary belt sanders.

Edited March 31, 20215 yr by Wichman3
brain death

ignoring the fact that manzanita root will probably contains stones and dirt, I think I'd make a jig to securely hold the pieces on a sled for the table saw (or band saw). Use that to obtain a flat side then start working from there. A cross cut sled and clamps would be my choice for working with the small pieces.

I have taken great care to dial in the accuracy of my table saw and go to that for squaring anything.

I would use the bandsaw to get things roughly to shape and then use the table saw. On the table saw I would make a simple jig for the sled to hold things and keep the fingers safe. As Lew said there is going to be a fair amount of soil in those burls so I wouldn’t use my best blade. 
Paul