I've also hand-propped 172s etc, and I do that from behind as those engines are not easily hand propped and it's safer to do it from behind.
A Gipsy is a long-stroke plonker of an engine and hand-props nicely. It Flicks round a compression at a time and bounces to a firm stop between compressions. It feels 'right' to stand in front, put the flat of one's hand onto the upper blade near the tip (never curl fingers round the blade!), give it a firm downwards pull as one walks away backwards and to the side away from the aeroplane (on a taildragger the blade comes closer to you as it descends if you are in front of it). If you stand behind it, it gets further away as it descends and one can't get quite the same 'natural pull through' as from in front, I find.
As the blade passes the horizontal you have walked clear and the blade will continue to complete a half-revolution even if the engine doesn't start (because of that nice firm well-defined compression). If the engine does start, it doesn't suddenly burst into full life but fires after the swinger is well clear, and gradually builds up speed to tick-over over the first few revolutions.
A C172 engine isn't like that. It doesn't have anything like as well-defined 'detenting' between compressions; it feels 'dead' and doesn't bounce round naturally half a revolution at a time. Best done from behind IMO.