I'm cross posting this in the Houseplant and Bonsai forums to request some expert pruning advice.

Some background: I live in a small condo without any outdoor space. Last fall I purchased a monterey cypress hoping to eventually train/prune it into something resembling a Christmas tree. I don't have space for a large tree, and I also like the idea of using a living plant rather than a piece of plastic or a dead tree.

This is what it looked like after purchase and after I tied it up (it was leaning over when I bought it):

{{gwi:7568}}
{{gwi:7569}}

Despite the bone dry indoor winters around here it did pretty well. Very few brown tips and it grew some. Here it is now (sagging a little bit because it's wet):

{{gwi:7570}}
{{gwi:7571}}

I have no experience in pruning this type of plant, and I was hoping someone can provide me some advice in helping it to fill out and take on a more conical/triangular shape. Specifically, where, when and how much I should take off.