If you're going to let it do its own thing and become a full grown tree, at least 40 feet away.

Or you can do as I do and prune off any longer shaped leaves so that it remains a shrub with only the rounded leaves used in flower arrangements. I think you are supposed to be able to cut it to the ground--someone with more knowledge than I have will tell you, I'm sure) but I haven't done that with mine, which is shaped like a stick of candyfloss!

I've done both - a lollipop 8 foot tree, and a shrub, cut to the ground every March, when it would grow again by 7 or 8 feet by end of summer

As above if a large species. If its a small one like E. moorei nana, much less of course.