As previous posts have shown, there are loads of ways of doing this journey and I suspect some will be better (or less bad) than others. Here are my ideas. - East Dulwich to Tulse Hill to Mitcham Junction then tram - 37 Bus to Herne hill then train to Mitcham Junction then tram - East Dulwich or Forest Hill / Honor Oak Park to West Croydon might be possible, but be warned that the tram is one way via West Croydon so it will be a longer journey on way out than back.