I like to say 'D-Plane is alive and well in the Putting Stroke.' The big thing about D-Plane in the full swing is basically it's telling us that mastering the control of the clubface is what seperates the great ballstrikers from the rest of the world. In putting it's very, very similar. Master controlling the putterface and you're off to a very good start. The only difference is that things like touch and reading greens are a factor as well and you need to master those to become a darn good putter.
One way you can learn to fix aim bias is buy getting an Edel Putter (www.edelgolf.com). Edel Putters use a fitting process where they have pretty much a countless different combinations of putter heads, hosels, aiming lines, etc. The process consists of finding what combination allows you to aim perfectly square to the target with you natural address position. Here's a video showing the fitting process.
The one drawback of the Edel putters is that they are quite expensive. In fact, the Vari-Loft design (a putter that allows you to manually change the loft -- shown below) retails for about $800.
That being said, if you were to get a Vari-Loft and your aim is now square to the target almost all of the time and you can change the lofts based on the speed of the green, you pretty much have the last putter you would ever need. The Scotty Camerons seem to be the favorite choice of golfers and they usually retail at $299 and golfers seem to change them out about once every five years or so. The past 12 months alone I have purchased 4 putters (Cleveland, SeeMore, Bettinardi, and a Yes!) and they have cost me about $500 total. I am really digging the Yes! putter, but my aim is not perfect with it by any means.
If you can't afford an Edel Putter and/or there's not an Edel fitter in your area, then I would suggest that you should dissect the problem by first establishing what your aim bias is (if you have any at all).
I would suggest either getting the Laser Putting Alignment System (aka LPAS) at http://thesmartgolfer.com/lpas/overview.htm
Or you can get the GTA Putterface Alignment Laser at (http://www.golfjustlikethepros.com/GTA%20Putter%20Face%20Alignment%20Laser.htm) NOTE: They have lasers for heel shafted and center shafted putters. You need to tell them what type of putter you have.
Once you establish where your aim bias with the laser, now you can start figuring out what's causing the problem. If your aim bias is square and you are struggling, then I highly suggest to look at your shaft lean and your skid-roll on your putter. I did a post awhile back telling how to get fitted to help eliminate the skid in your putts (http://www.golfjustlikethepros.com/GTA%20Putter%20Face%20Alignment%20Laser.htm) If you get putter fitted to help eliminate skid and you still struggle, then you likely have a major problem reading greens and/or developing touch.
According to Orr's studies on putting, most right handed golfers tend to aim left of the target (55%), while 25% aim right of the target, and only 20% aim at the target from only 6 feet away. In a recent post by Orr over at his forum, here's what he said are possible reasons why a golfer may be aiming left of the target with the putter:
1) Ball Position too far forwardObviously, if your aim bias is to the right, then the opposite applies.
2) Backward leaning shafts
3) Certain hosel types
4) Certain (putter) Line Configurations
5) Neck Tilt Left
6) Upper Spine Laterall Left
7) Asymmetrical Wrist/Forearm/Elbow/Humerus/Shoulder Alignments
I also suggest that you learn how to properly head swivel to help with alignment, this video shows the proper head swivel.
Once you get the aim bias down and make steps to correct your address position if it's necessary, I would then try and bring the laser alignment aid to the golf store and put it on putters and see if you can find one that can align you properly. The general rule of thumb is that if you aim left, you need less offset on the hosel and may even need a center shafted putter. It's amazing how many golfers I see who clearly aim left of the target and are using an Odyssey 2-Ball putter, with the thinking that the 2-Ball helps them align better when it actually hurts them because of the hosel configuration.
OTOH, if you aim right of the target, then you need a putter with MORE offset and you may want to consider a mallet type of putter. From my experience, you should stay far away from center shafted putters and blade style putters.