I learned from a top pro, he used to take a brand new disc, go to an area of grass and he would throw it down on it's edge as hard as he could about 10-15 times. Then he'd say, "good, now this disc will fly like I've had it for a month." He thought it was the best way to season a disc, short of hitting trees or a wall.
If the disc you want to break in is candy plastic then you will need some patience.
The break in process is a bit mystical to me. I have noticed that discs naturally broken in seem to work best. Artificially quickening the process is risky because once you go too far you may not be able to recover lost stability.
I agree that the most important factor is the nose angle, hence the advice to bend the disc up or down. Two other things seem to matter also but to a lesser degree: wearing away of the bottom edge of the disc (where the bead would be in a disc which has a bead) and warping of the outer rim.
A couple things which I think have less impact on stability are warping of the flight plate and gouges/nicks in the outer rim.
None of my opinions are scientifically based, they are experience based. If I wanted a disc to flip a bit more I would bend down the rim and test it. If it didn't change enough I would play skip in the parking lot and test it. Throwing at high speed into trees or brick walls is too risky a method for me. I have seen discs ruined this way.
The problem I have with the bend-the-rim-downward method is I have little faith that change is permanent. I don't know if I should keep on bending it before I throw it or trust it as is.
An odd thing I have noticed is when a disc gets a bit too understable for its spot in the bag, by pulling it out of the bag and sticking it in a box for a couple weeks, it seems to recover its stability. Either it flattens out a bit or it gets so bored sitting in the box that it tries harder to fly well. :)
The problem with the microwave method is that you have to guess how long to zap it. Zap it too long and you distort the shape of the disc and may make it unusable (in a practical sense, it may get crazy overstable).
What that method relies on is plastic memory. It sounds funny but plastic memory really exists. Lay the disc flat and pour hot water on it and its memory brings it back. This works best if a disc has been warped by sitting funny in a box, bag or pile.
"An odd thing I have noticed is when a disc gets a bit too understable for its spot in the bag, by pulling it out of the bag and sticking it in a box for a couple weeks, it seems to recover its stability. Either it flattens out a bit or it gets so bored sitting in the box that it tries harder to fly well. :)"
hahahaha!! so true.
and yeah, I Don't recommend nuking your discs. I tried it once, upon some advice on dyes from discgolfreviews.com and it kinda messed up a disc.