One of the most useful items here is the Harry Potter invisibility cloak. When I started I had a lot of issues with the cloak disappearing from my inventory from using a Razor macro and it desyncing - which often resulted in death!
In order to fix this I changed the macro to the following, and it rarely occurs now:
Exec: Drop what you are currently holding
Lift 1: (Cloak)
Equip to: (slot)