Q: How do you keep the dwarf Alberta spruce trimmed in a unifrom spiral shape?

A: Hopefully you've got one that is already trained this way -- it'll be easier for you to continue this process than to start from scratch.

Basically, with a careful eye you can maintain the spiral nature of the shrub through continued, meticulous pruning.

I would purchase a good set of pruners small enough to make very fine cuts. You can also buy spiral forms (available on-line from stores that handle topiary supplies) to act as a guide for pruning, like a template does.

Then, it's just a matter of keeping at it when needed, sculpting the shrub as it grows to keep it full and green.

If you end up enjoying this type of gardening, I'm guessing you would enjoy bonsai as well. I also suggest checking at your local garden centers to see if they offer any classes for specialty pruning such as this.