Two surprising things I found that improved my imaging and staging...

Generally speaking broad dispersion speakers require little to no toe in. I learned this with my Monitor Audio floor standers

How about 2 shots of cognac and relax?

There is a local dealer that specializes in Master Setting speakers.

I started out with my speakers closer to the back wall and as soon as I placed them 18 inches from the back wall and measure each speaker's distanced from the left and right wall they really sounded significantly better.  I also made sure they were both pointed exactly to the listening position.  

+1 sns and baylinor

baylinor hit the spot. And I'll second the recommendation of Jim Smith's book. In any case, it is certainly true that room acoustics are too often an overlooked element in one's system, every bit as important as any component—and "free" to experiment with. Of course, unless your listening room was purpose-built, there will be compromises, the notorious WAF being one (hence, not completely "free").

I have a pair of Scientific Fidelity Tesla speakers that I love, even against half a dozen high-end replacements I've auditioned in my listening space over the years and decades. You've never heard of these, probably, because Corey Greenberg gave them a bad review in Stereophile when they came out, and Mike Maloney's new audio company never recovered. But, at least in my space, they handily out-perform speakers Stereophile and other magazines awarded various accolades to, and which cost orders of magnitude more.

Mr. Maloney recommended toeing in his Teslas, and I've found they sound best toed in even more, to the point that their trajectories meet about two feet IN FRONT of my face. Their one deficit is that they tend to be a bit bright in the upper midrange, and this is tamed somewhat by having them off-axis. Also, extreme toe-in improves imaging for listeners sitting to the immediate left or right of the sweet spot, since that set-up has the more distant speaker facing the off-center listener straight on. Finally, this configuration is surely made optimal by my unusual room: very high trapezoidal ceiling, with the speakers sitting at the left and right of a large stone arch that opens into the entrance foyer of the house, so there is no wall behind them (although there are side walls, from which the speakers are several feet distant). Imaging with this configuration is simply astonishing. I can "watch" particular instruments (with eyes closed!), which makes it easier to follow individual lines of counterpoint. The clarinet is clearly sitting to the left or right of the oboe, and the horns are clearly further back. Such imaging is much more vivid than it would be at a live concert, and yet feels in no way "enhanced" or unnatural.