Around Oct. 1 is the prime time to get your CC as ready to bloom as possible. Also called zygocactus in reference to the zygomorphic blooms.
One thing you can do is to remove any immature sections from the tips, called leveling. They come off with the least damage for me when I twist them off. Using this pic as example, for this stem, removing the two smaller new sections should result in more blooms. Otherwise, it's likely that neither of these young sections will produce any blooms, resulting in no blooms for this stem if they are not removed.
Blooms form on the mature sections.
The plant may be small, but if the tip section is full-size, it can bloom.
The other requirements for blooming includes some fertility
, the next couple of months are a good time to fertilize CC's, just don't overdo it. A little is good but too much can make plants ill.
Your plant will also need to be in a place with great light during the day where there is also at least 12 hours of darkness w/o artificial light @ night
. The length of daylight vs. darkness is what triggers CC's to bloom, so if you can avoid exposing your plant to light while it is dark outside, your chances of getting blooms (assuming the plant is healthy) will be good. Put a box over it, or put it in a closet when it is dark outside if the only place for your plant is in a room with lights on when it is dark outside.
There is another plant called Christmas cactus, and some will say the Schlumbergera truncata of this discussion isn't the "original CC", and that S. truncata should be called Thanksgiving cactus to avoid confusing it with the other plant and because S. truncata more usually blooms around Thanksgiving than Christmas, and those are fine discussions to have. I just wanted to use the most common nickname for this plant, by which millions are sold every year.
The other CC is not as widely available, only blooms in pink, has pink anthers, actinomorphic blooms, and does not have points on the foliage. Christmas Cactus (Schlumbergera x buckleyi)