I've never done this. What I've done in the past is have two forums on the same host. I'll have a live forum that I'm actually promoting and working on, and then I'll have a test forum just for me and the staff to screw around with, whether we're testing out new features or trying to resolve technical issues by trying out problems ourselves. Being on free hosting, all I have as of now is a sub forum in the Staff lounge where staff and I can screw around and test stuff. No need for a full-fledged forum when you're on free hosting.
I have never done this before. I couldn't tell you why, but mostly because I just never thought about doing it. I always just find a good host and just do it that way. Like I said, I just never really thought about doing it. Sounds useful though, for like bugs and what not before actually hosting it.
Never done something like that.
I prefer installing everything on the web and testing it also, because you might want to hear opinion of someone else, and how is he going to see your project if it's hosted in localhost? 😀