We have a "wild" patch that grow under a loquat tree in pretty deep shade.

We've been here six years, and in those years, only a couple of flowers have been viewed by me. I have moved plants to various areas:
1. dappled morning sun, mid-afternoon shade, late afternoon sun
2. full sun starting about 1pm

Number 1 haven't flowered, though I did get many of the babies I planted in spot 2 from that area.
Number 2 haven't flowered, and they did have an adjustment period, during which they looked pretty rough. They seem awfully happy now, though.

In fact, plants in the original patch under the loquat seem happy, too. They're all happy.

Just no flowers for me. :(

Can't wait to hear suggestions.

Well, seems like I lied a bit. The ones in full sun all afternoon (2) aren't quite as good as the others. The leaves have spots, where the other plants in the different exposures don't.

Here in Mississippi, Crinums do best in full sun or in morning sun until mid afternoon.

There are several things that affect blooming. First, the bulbs have to be quite large. It is not unusual for it to take 2 to 5 years for a bulb to bloom after purchase, depending on the size of it when acquired. On the other hand, if it's a very large bulb (softball size), it can and may bloom the first year if put into excellent soil, sun, and water conditions.

Crinums will tolerate drought, but they bloom better with regular water.

They really like nitrogen, preferably in the form of manure. If you will topdress the plants in the fall with an inch or two of manure around the bulbs, they will reward you with earlier and more numerous blooms the next year. They won't say no to a dose of liquid nitrogen sometime during the summer too. They also appreciate a good mulch, though they will tolerate growing in the middle of the lawn.

The longer a bulb stays in one place, growing in size, adding offsets, etc. the better it blooms. It's best to plant your bulbs and leave them in place for as many years as possible. Digging and dividing can very commonly cause them to skip a year in their bloom cycle. If you do divide them, you must dig up the entire clump (not an easy job) and then pull off the offsets. Always keep the largest bulbs or you will have a multiple year wait for blooms.

Finally, it's good to know that there are dozens and dozens of varieties. Some bloom only once a year. Others bloom repeatedly. Some take 6 square feet of space for their bulbs, others take only 18 square inches.