Well on my old account I basically disenchanted every cards except commons and maybe some rares I didn't need to disenchant to make a quest rogue deck and I got bored of it really quickly so now I had an account with no cards except commons and rogue cards :L. I decided to move to another region to start again and I'm doing well, I bought the One night in Karazhan adventure and I'm saving up cards and I only disenchant cards that are bad/cards that I know I wont use in the near future, so you keep good cards for decks and disenchant bad cards for decks.