About to sell my phone, need best way to completely wipe data.

[AC Question]

I am selling my Samsung Galaxy S3 phone and I just factory reset it. But I found some websites saying that encrypting the phone and then factory resetting is the best way to do it. Is there any way I can encrypt my phone's previously wiped data?

 

[BattleSwine]

The ultimate guide to selling your Android phone or tablet | Android Central

 

[LucidPsykosis]

I was told by a guy at Kaspersky, that encrypting your phone before you factory reset is the most secure.