Does anyone know the best way from experience to get amaryllis to bloom once again? Do they have to grow in soil?
The one that I had only bloomed once and produced leggy pale green leaves for the following years.

They are heavy feeders, you should be feeding them regularly while they have green foliage, this helps build up the bulb to produce flowers.

yes, a lot of soil and a lot of nitrogen nutrients. And of Couse a lot of sunlight , bulb has to regain it strength , blooming take a lot of energy from the bulb.

Sue and Ron gave good advice. The buds are formed the summer before. Pale green leggy leaves suggest not enough sun and not enough fertilizer in the summer. They can stay in the pot year round, as long as the other conditions are met. Don't let the pot dry out in the summer.

Thank you everyone for the advices. Though it should had been obvious to me that I was treating them like houseplants instead of spring bulbs. I gotten a new amaryllis that was on sale after the holidays recently. The strange thing is that it hasn't sprouted or bloomed but still a small premature sprout tip. Could they have been late shipments or sprayed with something to prevent them from sprouting?

When they are a little slow, I found bottom heat helps (I put mine on the furnace)

Occasionally you do get a bulb that is very slow to show signs of life. I have a new one, Bouquet, that I got back in late October. It is plump and green but is the lone bulb that hasn't broken dormancy yet. Come March, I will plant it outside with my other new bulbs (zone 9A) and see if it will eventually get going. Heat on the bottom of the pot right now might help your bulb.

I second Rj and Barbara on some heat, so I pulled out an old message from a previous thread showing my high-tech 'Hippeastrum incubator' for those slow or stubborn starters. With the black plastic of the pot absorbing sunlight on a sunny day, the pot gets warm to the touch after a few hours, and the reflected sunlight can get very bright. I sometimes use a little foil to direct even more light. Remember, if you bought the bulb after the holidays, it may have been in that store dormant for many months and need a little coaxing.

kenisaac said:
I also sometimes put the slower plants in the south facing windowsill, then place an old white plastic lawn sign or white cardboard on the inward side (pinning the pots between the window pane and the cardboard) to reflect the light and warmth that streams in back towards the pots. They often really respond to this.

My wife said it doesn't look beautiful...

And, no, the incubator still is not beautiful.