I'm a 'starter' but I'm also a 'finisher'....just not necessarily the same project!
Right now I mentally counted up at least 15 quilts that are in my "UFO cabinet", but by Christmas I'll have all but maybe 2 or 3 of those finished. (And I will probably have started 5 or 6 more!)
I like starting new projects, I like finishing old projects...I do get bored working on the same thing though, so for me it's best to have several things in motion at once, so no matter what mood I'm in there's something to be worked on that suits my current mindset. Sometimes I'm good at working on really fussy things, sometimes I want something simple where I can put the pedal to the metal and zoom along recklessly. So I have a couple projects of each type and all sorts of things in between, ready to be worked on.
I store my UFO's in a cabinet with glass shelves so I can see everything. Each project is put together into a kit and sits on a tray, so it's easy for me to pull a project out, work on it, then put it back into its spot when I stop again. This works up until the quilt is sandwiched, then it's too big to fit and ends up living loose in my sewing room, getting shuffled from place to place. For that reason, once a quilt is sandwiched it tends to get finished quickly, because it's in the way!