Markings where the socket user can see them are mandatory. If you don't like the ugly blue stickers that come with GFCIs, get smooth white cover plates and a thermal labelmaker.
Use the labelmaker to make
GFCI protected and
No Equipment Ground labels on white background material. They will look professional and like they're part of the cover plate.
GFCI Protected stickers are needed when a GFCI device is used to protect additional plain outlets downstream in the circuit. Did you know you could do that?
While you're labeling, add a label for the location of the GFCI device, so people can easily find the RESET button.
If it's coming as news to you that GFCI devices can protect downline parts of a circuit, and that you only need one GFCI per circuit, then real simple: Do not use the
LOAD terminals. They are not "extra terminals for the other 2 wires" -- they are special, and for wizards only. Just like the warning tape says. If you have 2 wires to attach to the 1 line "hot" screw etc., then use pigtails.
LOAD terminals without really knowing how GFCI works, will endanger the success of your project by introducing lots of hard-to-understand complications.
The worst thing you can do is daisy chain GFCIs so each one's LOAD feeds the next one's LINE... That will make the network very annoying and confusing to use. It's also a "Yo Dawg" joke.