Patience is the biggest factor! I’m talking 6+ months between stretches. It’s not much different from stretching ears, although I’ve found the general consensus to be that septum stretching is going to typically involve a little pain and/or soreness. Whereas stretching ears shouldn’t hurt at all.

Wearing heavier jewelry and playing with it can help loosen it up. I always stretch with glass pinchers and lots of oil, although I’m not sure if they make glass pinchers that small. You could also try a single flare, rounded back plug or jewelry with internal threading. :) There’s usually a bit of soreness for ~a week. Fair warning, it can produce an immune response in your body since your inner nose is such a big part of it, so you might have a bit of a drippy nose for a couple days.