Ah well what worked for me was just getting a stack of 10-12 putter (not all the same but wouldn't matter if they were) and just throwing for 15-30 min every night over the summer. Experiment with stances, hyzers, anhyzers, and lofty s-curve putts. Just try everything. I know one of my friends started putting with his feet a little wider than shoulder width apart and keeping the disc directly in front of him and the basket, starting low and bringing it up about to his chest and letting it go.
I personally use this too when the putt is <20 feet or so. It is fairly easy to keep the putt straight. Other than that, just keep practicing and you'll find something comfortable for you.