Ours didn’t flower this year so I am thining I didn’t let it hybernate properly:
Advice according to LJ:livejardin
Put the amaryllis outside when it warms up, in a place where it will get absolutely blasted with sunlight every day; the pale indoor leaves will probably die off but keep watering and fertisilising and more will grow; fertilise it heavily from August onward; when it threatens to frost outisde bring it in and totally stop watering it, I mean completely. The leaves will die off. Let it sit that way until maybe Jan or Feb, then give it a good watering and wait for the flower stalk. If it doesn’t bud within a week, give it another watering - that should do it.1
Rinse & repeat. I’ve had one going for 10 years. Occasionally it needs repotting and separation from its babies.