I relate so much to the OP and I think it is a very common issue. I look at many system pics and wonder what the heck guys are doing with all those traps/tubes/diffusers/panels etc! From my experience, they all have their own sound and more often than not when I try to bring them into my space I screw things up more than help. I have read many of the popular, suggested, articles and still no zilch about measuring sound other than what I hear. I envy some of the members with more technical backgrounds who do in fact know how to actually tune a space but man am I far from that. So...the solution I found was the panels from Furutech + Acoustic Revive. They do not resolve all issues but along with my floor to ceiling drapes, big couches and rugs, seem to bring a big improvement in overall sound in my space. They offer a few simple suggestions on placement which I used as a baseline and no measuring was necessary. Of all the stuff I have tried, these "devices" are by far the best for me and the impact is quite dramatic. Bonus is they look very stylish too! So that is how I compensated for my lack of scientific knowledge!
Room Treatments
I don't really know anything about room treatments. I have done some reading but still confused. I guess my main question is how does one know if they need absorption or diffusion? I have a tv hanging on the wall behind my speakers how does that effect things. Am I better off going with traditional panels and traps, or should I be looking at resonator devices?