If the cockpit is all finished and the canopy will be closed, go ahead and mask it and paint. If you are going to have an open cockpit, paint then install the canopy. Leave the props off till after painting as it is hard to mask around them without damaging something.
Berny
Phormer Phantom Phixer 
On the bench
TF-102A Delta Dagger, 32nd FIS, 54-1370, 1/48 scale. Monogram Pro Modeler with C&H conversion.
Revell F-4E Phantom II 33rd TFW, 58th TFS, 69-260, 1/32 scale.
Tamiya F-4D Phantom II, 13th TFS, 66-8711, 1/32 scale. F-4 Phantom Group Build.