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There's the burnishing tutorial. 
Burnishing is the process of smoothing the edge(s) of leather.   Using heat (friction), moisture, and pressure you get the fibers to lay down smooth.   I als use a cocobola burnisher I made, some folks use plastic.  Dress the edges (make them even, pretty smooth, and round the corners) using sandpaper, a file, or something similar.   Before I bought a belt sander, I used a Stanley Sureform, and it does the job.  Once dressed, I use my little burnisher to do the grunt work and shape the edge.  Then, I switch to some scrap denim for the last step.	Read and try Bob's tutorial, it'll explain a lot of things.  Since reading his work, I changed my method to the one he teaches....with substitutions where needed for tool availability, et al.