As is probably not uncommon, something I should have taught myself early on has come later. After really coming to the understanding of what truly sharp hand tools can do compared to the ones you think "are probably sharp enough", I have begun trying to clean up most of the edges on my chisels and planes and get them at least to a state where a quick touch up will keep them good and sharp.

I am using the old marples blue handles, which have been good chisels for the money. In the case of my 1" chisel, I began trying to restore its edge the other night(it has seen significant use, and was very dull). I was using my new Norton 4000/8000 combination stone, my veritas Mark II honing guide set to 25 degrees, and my old, off brand home depot stone that I would imagine is close to 220 grit. I used this stone to remove a lot of material and then proceeded to the 4000/8000. After discovering that the edge was slightly out of square, either from the box or as a result of some horrendous and misguided previous attempt at sharpening, I reshaped it with a file, then proceeded to hone away at the now completely dull(but square) edge. The long and the short of it is that after quite a bit of rocking back and forth over the workbench, it is now as sharp as a razor...and crowned. I am in the process of cutting a lot of dovetails right now, and noticed as I set it in the first back line that it has a fine, but noticeable crown.
What improper technique did I likely employ to create this? How do I avoid replicating it in the future? Thanks in advance, you guys always have constructive and thoughtful advice....