I've tried several types of coupler on my N gauge stock to avoid the hand in the sky approach, Cruikglen will feature two stations where shunting is required, as well as the engine shed.

To date the most reliable have been D&G type, although I've found them very prone to damage. I've recently been experimenting with the new Dapol magnetic couplers and have found them to be excellent. With care in setting up the magnets and couplings themseleves reliable results have been achieved even with the magnets below the sleepers.

These photos show installation of a Dapol magnet in the shed area.