I build both for myself and for the Gallery. Though, I've only built a couple of community lots, a restaurand and a museum. For restaurants, I always plop down Maxis builds, after reading so many people having trouble with them from the Gallery.
With homes, I never use MOO, but I do use alt-placement for some decorations, outside plants and also some times for things like accent tables, livingroom chairs/sofas and coffee tables. I've never had routing issues at all from using the alt-key to place anything. I like that instead of MOO, because you can't place things where it absolutely shouldn't be placed. I make sure there is enough space to move around and that sims can use whatever it is they need to interact with.
For homes I use for my own sims, its more about function than beauty. I add the essentials and anything else my sims need for skills and hobbies. Decoration is not really a priority, as long as things work the way they should. Still like nice homes, though, but I never use much clutter and things I don't feel is needed in the home.
