My friend once told me ´Buy a ticket to South Queensferry, cross the bridge, walk around and then stop by in Dalmeny. Just tell to the ticket guy that you will be stopping in Dalmeny and then continue to Edinburgh. He should be fine.´ As person who doesn´t like conflicts (in a case one would of happen with ticket guy) I wasn´t very sure about this idea. But I took a risk.
Edinburgh itself offers a lot of interesting places to visit. Do you want to explore deeper and more father? Just by train or bus distance there are amazing places which shouldn´t be abandoned in Edinburgh´s shadow.