Avoid common English language mistakes.
More details: Writing: English language
2. Consistency, organization, and visual appearance
Use consistent font face, color, and size.
Use consistent casing.
Use consistent punctuation.
For example, have a clear logic for using dots at the end of each bullet point phrase.
Try use only one to three colors.
Keep only phrases and words that add significant meaning.
Use positive words instead of negative where possible.
Make sure the words you mention are known by the typical reader or make sure to explain them.
Consider keeping abbreviations only for very commonly used terms in your field or for searchability (making sure your resume shows up for keyword searches). It looks like Elon Musk didn't like acronyms too. Here is what his email about acronyms to the SpaceX team allegedly looked like: ASS (Acronyms Seriously Suck).
OK: SQL or CSS.
Not OK: BDD (Behavior-Driven Development)
Use the language and structure that is as simple as possible, but not simpler.