Seriously, paper and pencil... then move it into the app that lets you design an Arduino pinout. (@Deva_Rishi / @johnerrington ).
Maybe write a "beginner how to" for a pencil-drawn schematic showing what will convey the needed information for a post, and post it here. You will be adored every time a novice thread starts with a schematic using your design.
(edit - as a matter of fact, a couple layers deep through "how to get the most out of this forum" @johnerrington shows "how-to move paper and pencil to online schematic")