I know this is probably just because I'm lazy, but I find that adding lights to my craft is the least fun part of construction and can be the easiest to forget and it also happens to be the detail that increases the realism and playability of the craft after it's in space. Would it be a good idea for fuel tanks, command modules, and docking ports to have point light sources that would not increase the polygon count. That would give a general level of visibility to the craft without having to add obstructive looking light fixtures to the edges of hatches. Feel free to tear into my idea...and...GO!
