UI themes

Set up themes within your UI to indicate when you have all of your Auction house and crafting addons loaded and when you have your questing and dungeon running addons loaded.  
This is easy to accomplish with Addon Control panel.  Just select what addons you use for each task and save them as a profile within Addon Control panel.  
I use EliteFrame to indicate when I am in crafting mode and Shadowed Unit Frames for dungeons and raids. 

Crafting Mode

Questing Mode