In the case of your lil guy here, I am leaning left...
It's not because of the scar really, I just like the balance a little better from that direction. It's more extended in it's arch and I think will look interesting as it grows over the edge of a pot some day.
I am curious though, is this a standard alder, or some kind of varied direction variety? I'm just trying to imagine how you will deal with it's growth habits, as the alder I have here is very much a upright tree...
I once had a dear friend council me that it was ill advised to attempt to get a tree to be untrue to itself. He was perplexed when I told him I was getting ready to do a larch as a cascade. However I showed him pics of it and then he understood my goal, because my tree is a european varied direction larch. Then he gave the nod and told me to have at it. lol
Kind Regards,