Exploring Interesting Chords with Simple Formulas

[MetalPlayer]

I recently came across a video that explained 13sus4 chords in a very straightforward way, showing that you can derive them from a Maj7th chord by playing it a whole step below the root. This little trick has added a lot of colour to my music, and I'm curious if there are other formulas out there for unique harmonies that are just as easy to grasp. Does anyone have suggestions for interesting chords that can be easily applied in songwriting? I'm looking for practical advice since I find chord alterations tricky.