~S~ Dave, cockpit bars/frame , yup use modellers masking tape if your brushing and tape plus masking liquid if your spraying M8.
The real trick is to spend time filling and sanding all of the major joints, (fuselage halves, wing halves ,wing to fuselage joints etc.)
Let each coat of paint really dry before over painting with another colour.
Use the decal solutions you can buy from a model shop to get them to mould to the aircraft surface, (follow instructions on the bottle carefully and don't panic when they crinkle up ) LOL
Leave the cockpit off until the very last .
If you can spray the last coat of silk finish lacquer over the whole surface including the decals it will help give the plane an even scale shine.
Weathering should all be done before this last coat also.
As I no longer have an airbrush I managed to buy a little can of silk lacquer from my local model shop, the nozzle was truly crap and kept clogging !!
As you probably realize, spraying the whole thing with an airbrush is the way to go but a bit expensive for a one off model.
Feel free to ask about any specifics M8 , no problem