Requires CTD Core 2.1.1+
That's Where I Was! adds a set of items, called Memory Recall. It has a finite durability, but it allows you to store your location and teleport back to it at any time. How neat! Sneak+Right Click to set location, and Right-Click to teleport. Uses 1 durability per teleport. Maximum durability is defined by the tier of the Memory Recall, with more expensive tiers having more durability.
HOW TO USE
Step One) Sneak Right Click to set location. This is set per item, so you may share these with friends.
Step Two) Go away from where-ever that location is for maximum efficiency.
Step Three) Right click to warp back to location saved in the Memory Recall.