hi there Steve, really I think it depends on the type of model you are building - whether it be a ship, boat, fishing trawler or whatever. On some models, you may have masts and may be able to run the antenna/aerial up the inside of the mast.
On my Fairmile B I have ran the aerial along the deck edge close to the railings. Yet to be painted and camouflaged in.
On WW2 HMS Ajax, the aerial actually makes up part of the ant-magnetic mine cable (degausser) that runs around the stern of the ship.
On the MTB, its actually coiled in a loop underneath the forward Carley Float; that may give you some ideas of how to camouflage them in.
Your question Steve, actually opens up another topic.
In the instructions that come with your RC set, It should state that your RX, receiver (aerial) should be stretched out as full length and vertical as possible.
However, on some models, this is not practical. The main thing is though - try and keep your aerial wire away from electrical noise making equipment in your model (noise making i.e. electric motors/relay switches/any item really that does or can produce a spark.)
As a footnote; the aerial wire that is wrapped around the Carley float on the MTB, this is a Futaba 6-channel receiver and I know for a fact that this model has well over a quarter of a mile range.
Just some food for thought for you my friend.
Aye
John e
Bluebird