A mix of everything. On my alt character I did Fates/Leves/Area Quests/Dungeons. As a DD you will sit in queue for a while, plenty of time to do the leves, and with the new Fate system making things scale, you really don't need to be in a "Fate party" to get gold anymore. At least at low-mid levels. Once you hit Coerthas it might be worth fate partying again. Make sure to do your daily roulette!