It sounds like you're reasonably comfortable in your airplane as is, but you want to expand your flying some.
I agree that flying with a good 180 experienced CFI is a great idea, but there are some things you can do yourself.
First, as Barnstormer noted, learn to fly the airplane precisely. That means EVERY landing is precisely where you want it, every time. If you're going to miss your spot, go around. To do that you have to be very comfortable with the landing configuration of your plane. Work on that at altitude. Lots of slow flight, with the stall horn blaring, including maneuvering at those speeds. It's not that you'll be flying a long final at that speed, but you need to feel where that bubble is.
When you land on a runway, pick a center stripe......not the whole center line....choose one stripe, and touch down on it, at minimum controllable speed. 10 K foot runway? Pick a spot close to your desired taxiway exit, and land there.
Now, find a grass runway somewhere and practice one wheel landings. Nice calm day, land the airplane nice and slow on the left main, and only the left main. Run down the runway on the left main, don't let anything else touch.....then lift off.
Now do the same on the right main. Then switch to pavement and do the same. Really long paved runway? Touch on the left main, with the left main right on the centerline, then pick the plane up, move over, and put the right main precisely on the centerline, then pick it up, and put the left down, etc. till you run out of runway, go around and do it again.
If you're not comfortable trying that yourself on grass first, get with a good instructor who'll work with you on it.
Once you can master touching precisely where you intend to touch, and you can touch and run that airplane down a line on one wheel, you'll have gotten pretty comfortable in your airplane.
Again, if you're not really pretty comfortable in your plane to start with, find an instructor who'll work with you to GET you comfortable.
As far as expanding your envelope, once you're comfortable in your plane, it's generally a matter of gradually taking on a little more at a time, then evaluating how that went, then push a little more, etc.
Flying with an instructor helps, but most of the expansion of your flying is likely to be done by yourself.
MTV