Maximising your quest gold
For the solo player:
- Leave as many quests as possible to do at level cap (Classic/Outland/Northrend).
- Do all quests in all zones as you level. Only abandon quests when they're close to going grey.
- Get an addon which tells you which is the most expensive reward (extra vendor gold).
- Do group quests as soon as possible.
For the group player:
- Kill mobs that drop cloth (always in high demand)
- Run instances