We have two to avoid Penge then Crystal Palace Hill..can't recall Road names, sorry.
Turn left after the Tesco Express on the way to Penge. Turn right and the mini roundabout, carry straight up till you get to the Travelodge on the Croydon Road. Left then right takes you up to Homebase. When there you have a choice.
left takes you to Anerley. Go up the hill ( slow), then right at the top, second left takes you down a little road to join the main left turn from Crystal Palace and then out at the big roundabout.
Right takes you on to Crystal Palace hill. From there we take the second on the right, which takes you via that wonderful Pisarro view to is it Westwood Hill, but if Crystal Palace has roadworks or is slow, Westwood is usually better. ( if Westwood is the one up from Sydenham).
You can try the Sydenham Hill, down as if you were going via the Horniman but turn left instead, then follow the S Circular if going to DC or DCPL, Rosemead, straight ahead if Alleyns/jags.
None is brilliant.