I will keep these brief and to the point.
3D printer bed prep
Kapton Tape - Think of this like sheets of glue that activates when it gets hot. It’s also a great way to protect the 3D printer build platform.
3D Printer Slicers
The whole point of a slicer is to take the mesh and turn it into layers. Think of it like laying down the print .3mm at a time on an XY plane.
Cura (free 3D print slicer)- This software has advanced tremendously over the years thanks to open-source user input.
Simplify 3D (premium 3D print slicer)- I just got this, and have not seen the benefit yet for the common maker.
After the print
Whether you will paint the finished product, use it for testing a project, or a stand-alone piece, a completed 3D printed piece will need some cleanup.
Carving knives and knives for supports and rafts - I love the small lathe chisels to carve off the rafts and support material.
Makerbot has a great article on “How to Paint 3D printed pieces.”