Hello Everyone!

I've been a member of this forum since June last year, but this is my first ever post. Up to now I've been lurking about in the shadows, watching what all of you get up to, stealing all your ideas...

But now the time has come to step out into the limelight and ask for help!
To ask so basic a question is almost embarrassing to people who are such genuine craftsmen, but then again as my old science teacher would say, "No matter how silly a questions sounds, if you don't know the answer it's a good question", so here goes.
I bought a really nice Neptun model of the battleship Roma on Ebay at a very reasonable price. She's currently in the typical Neptun paint scheme, but I would really like to try to put some colour into her. I've been trying to figure out some way of putting the air recognition stripes on her foredeck, all the way back to the breakwater aft of A turret, but for the life of me I can't figure out how to apply the masking tape to the area I wish to paint. There are so many odds 'n' ends on the deck - AA guns, capstans, etc. - that I don't know how to get the masking tape on in a manner that will insure a secure seal.
So how do you guys do it... how do you get those stripes so razor sharp and precise on the decks of your models? Freehand? I hope not, I could NEVER do that freehand, and full marks to any of you who can. Someone suggested taking as much of the equipment off the model first, but although I need to check, I fear most of it is cast on, it would be a difficult task to try to remove it I suspect.
I don't pretend to be a brilliant painter, each and every one of you could produce a better paint job if you wear wearing a blindfold than I could even dream off, but I would like to try to make such an elegant ship look as good as I possibly can.
So lads, there it is! I'm really stuck with this one, I have not the slightest idea how to attempt this. ANY advice or tips you can offer will be a huge help to me and will be very much appreciated.
Many, many thanks in advance.