The literature has all sorts of suggestions--I've never followed any of them. But I've produced and enjoyed creamed honey many times over the years.
The trick is to get the crystals in your honey to develop quickly. When they grow slowly, large crystals form and then the honey becomes a "rock".
So how do you get crystals to form quickly and stay small?
My "secret" comes from the way I extract and store my honey.
Not being a honey glutton, I often leave excess honey in the combs and when the next extraction comes around, I have crystalized honey in the frames. These crystals come out with the fresh honey and get stuck on the top of my filter fabric. To get them to go through the filter, I press on them with a spatula that breaks them down and these small crystals mix with the honey in my collecting barrels.
When I bottle the honey, those bottles I want for creamed honey go into the refrigerator for several days to a few weeks. The result is a nice soft or firm creamy, non-spilling, easily spreadable honey.