How do you get to sm southmall from sm north edsa?

Ride the Train at North Avenue MRT station and get off at Taft Station (15 pesos).

At Taft Station walk to EDSA LRT Station. They are connected so its easy to find.

Ride the train (12 pesos) and get off at Gil Puyat Station.

Go down at the part of the station near JAC liner/Baliwag.

Buses (Tas, Bensan, Reinalyn, ATSC, Igan, WLH, WLLH and Maggi) that pass by in this area go to SM Southmall. You'll see their destination on their front Windows anyway. (I recommend Tas or Bensan buses. On average they're the fastest ones since they don't go on picking up every single passenger they see).

Bus fare is 38 pesos normally and 30 pesos for students/senior citizens.

Around 9PM onwards, Only Tas, Bensan, Maggi and ATSC pass by at Southmall.