Your UV-map looks just fine! I might have kept the top of the wings together with the top of the body but that is minor whine. Also like you said map has empty space so you could have compressed it further - this would also give some additional texture resolution because after compressing you could scale everything up a bit (to fill the UV-space completely).
I usually dissect my models with planar projections as far as possible unless it's a leg or something where cylinderical projection is the obvious choice. I try to keep everything in the same scale but some things like headlights & logos I might do X2 or X4 - this usually makes the whole model sharper.
Also I try to use as little maps as possible because multiple surfaces slow everything down, better use bigger map than two separate small maps. I don't like "pelt" style maps because they are impossible to paint by hand... but if I can generate and bake texture to it using coded/procedural stuff it's OK then.
I usually dissect my models with planar projections as far as possible unless it's a leg or something where cylinderical projection is the obvious choice. I try to keep everything in the same scale but some things like headlights & logos I might do X2 or X4 - this usually makes the whole model sharper.
Also I try to use as little maps as possible because multiple surfaces slow everything down, better use bigger map than two separate small maps. I don't like "pelt" style maps because they are impossible to paint by hand... but if I can generate and bake texture to it using coded/procedural stuff it's OK then.