If you are having your DK as your main then doing quests makes a lot of XP. Specifically doing kill and escort quest because those are very fast XP generators. Instancing may be a good XP generator for you since you have an overgeared main toon. The only problem there is that the XP will scale down a large amount because of your main.

I had an 80 warrior lead my pack of 60-70s. I did Kill, Escort, Instances and AV. No collections quests for me unless it was getting *ONE* item and it had to be gotten with *ONE* try. I hate NR collection quests the most.

Doing instances and AV will really sharpen your macroing skills. Especially a mixed party in AV.

Drommon