Just wrapped up my Little Bird build and the fit was rough enough that I figure someone else starting it might want my notes. First thing: throw out the instruction sequence for the fuselage halves. Dry fit everything, then scribe the mating edges with a sanding stick before you commit any glue. The seams around the tail boom and the cabin roof needed a couple passes with putty, and I only found that out the hard way by gluing too early. The clear parts were the worst offenders for me. I ended up masking them off and installing the canopy after paint, using a tiny bead of white glue instead of proper cement so I could pop it back off when it sat wrong. Saved my sanity.
Paint the pilot and any bench passengers before they go in the cabin, obviously, but also do the cockpit tub as a subassembly. It's way easier to detail a loose tub than to work through the door openings once the fuselage is closed up. Decals behaved fine with a bit of setter, and the external benches are a good spot to practice some wear and scuffing. Call mine done for now, though I keep eyeing the empty benches and thinking a couple of passengers woud sell the whole thing.