Actually, there are some legit hacks I've read on here, but I either can't find them or don't know enough to repeat them accurately (still working on instrument rating).
For example. There seemed to be several tricks one could use, legally, to get a desired routing that had to do with filing multiple flight plans, or filing from a point, or something. This is a "hack" in the sense that it exploits a behavior of the system in a way that's beneficial to the pilot.
As a VFR only pilot, one hack I like is using the OBS mode on the 430 to give me an extended runway center line. Helps even coming in to the home field when I can't see the airport yet. "Expect straight in 18R" means to me to intercept the centerline a few miles from the airport and go straight in.
Based on my (limited) experience, I found going to KORL (Orlando executive) to be much easier having already been on flight following. This is a hack (again, exploiting properties of the system in novel ways) because getting FF before I got to KORL meant I didn't have to worry about the busy airspace as much. Everyone along the way was expecting me. Can you do it without? sure. But man, it made it easy.
I'm sure there are others, and I'm intentionally omitting rules of thumb and shortcuts for calculating things. IMHO, what's being asked for here are ways to work the system that are legal, and safe, but not obvious.