Basically, two main concepts drove my recovery:
1) Allow the ligaments of the pelvis to rest and heal. I had to become very, very conscious of my movement patterns and learning to avoid performing motions that were likely to make my SI joints lock up.
The worst two motions for me were twisting, and anything that involved putting my weight assymetrically on one leg.
Sitting on cushy chairs or couches that were so soft you’d sink in really far was also a sure way to cause my SI’s to lock. Basically, anything that threw off their equilibrium and unsettled things.
The more I was able to cut back on these motions, the better I did.
2) Strengthen the surrounding muscles.