That is a great question. I only have a tiny one right now about 14 inches tall, but it does like to grow thin and tall. I'd be curious to see what others suggest. Have you been feeding it? Keeping it supported sounds like a good idea.

From what I read elsewhere is clipping back to no more than 8 leafs on any branch is a good idea.

But, if the plant is healthy you might want to create a trellis for it and give it more food.

Also, I can't tell from the pictures, but have you gotten any fruit or flowers yet?

Here is a link that might be useful: sunroomgardening.blogspot.com

Yeah I've gotten a few. They taste really good, and taste like it's names suggests, a lemon flavored guava. When I took this picture a couple of days ago I ate the last two fruit off it. My dog ate two others that were lower :( So it's ripening fruit here in January. Really looking forward to warmer seasons and more fruit production. It was last given some fish emulsion back in late summer.

How is your plant doing now?