Create Magic Item

The DM may require players to study the existing magic item first, before creating it, or undergo special training.
The DM may also allow players to design their own magic item, and present to the dungeon master before using it.

You can create one uncommon magic item over the course of 3 days with no rest, must be concentrating the entire time.
After cast, you cannot use this spell again for 3d8 days. (to a minimum of 1, with modifiers)

If cast at 6th level or higher, you can create a rare magic item instead, and at 9th level, you can create a legendary magic item.
Alternatively, you can decrease the amount of time required to cast by 5 hours, and stack a -1 modifier to the 3d8 roll for every spell level above 3rd.
You may mix and match these effects with multiple spell levels.