Add "New Guide Layout" option in "View"
I just learned about this in Photoshop! What?! Come on Illustrator, you have needed this feature since the beginning of time. Please Please Please make this happen yesterday!
Daniel Kitura commented
It`s really strange they didn`t copy this option from Photoshop (maybe they did in 2020 version, I don`t know), BUT
I just found a similar tool in the toolbar section on the left. It is called Rectangular Grid tool, and it`s located in Line Segment tool "folder" (see attached picture)
And here`s some more info https://www.youtube.com/watch?v=HX1QWAv3MOQ
Mohammed Al-Tahami commented
Virgil Ierubino commented
So obviously missing
I completely agree, would save a lot of time whenever you want to drop some custom grid to your format. I don't know why Photoshop has this option and Illustrator does not.