[Otto]

I don't recall any instructions on how to tweak manually. There may be some in the REW and BFD guides...

Really, there are only three parameters per filter to adjust: frequency, bandwidth and gain. When possible, I like to re-use existing filters that are nearby any peaks (or dips) that I want to adjust. If those don't work, I will dispatch a new filter to hit my target area. Usually I take a measurement, make a change and see what happened (and I maintain a way of going back). I generally only change one thing at a time, so that I know how it affected the overall response; too many changes and you'll lose track of the big picture.

After making a change, I remeasure and reassess. Did it cut too much? Reduce gain. Did it cut too wide? Reduce bandwidth. It's pretty easy to hit the right frequency, so there's usually not much problem there. Still, you might play with sliding a narrow-bandwitch filter around in problem spots.

Overall, it can take a while once I get going, if only because I enjoy tweaking with it. Of course, you can use REW's filter suggestions right out of the box and be pretty close.

Have fun!