The problem with beautiful, unused guidelines
Most brand guideline documents are eighty pages long and opened twice. The version people actually use is the one that answers the questions they have while working.
Aim for something a new team member can absorb in fifteen minutes.
What must be in it
Logo files in every format, with clear space and minimum size rules, and a short list of what not to do with them.
Exact colour values for screen and print, including which colour is primary and when the accent is allowed.
A typography scale with actual sizes and weights, not just font names.
Three or four example layouts showing the system applied to a real piece of work.
What can be left out
Long brand story essays, mood boards without instructions, and abstract personality wheels rarely change what anyone designs.
If a page does not help someone make a decision, it belongs in the strategy deck, not the guidelines.
Make it a template, not a PDF
The single most effective thing you can do is ship editable templates alongside the rules: social posts, presentation slides, letterheads.
People follow guidelines when following them is the easiest option available.