How for to multibox?

Long time solo boxer here, but I am sick of the non stop pain in the butt it is to transfer stuff back and forth between my characters. Plus it would be nice to be able to portal myself around. Any experienced box multipliers out there that can direct me to a trustworthy source or guide or something. I don't want to just download some sketchy bank devouring software off the street, I want the good software that minds it's own business.

If you've come to throw shade about multi-boxing, redirect that energy somewhere constructive. My actions are backed by $40 worth of conviction. Your cries will not echo here.

Edit: Issue is resolved. This post is exactly the solution I was looking for. https://www.reddit.com/r/fo76/comments/udc6at/how_to_run_multiple_instances_using_steam_client/