Throughout your LinkedIn profile:
1) No typos (should be obvious but I see so many of them!). Use Word’s spell check at a minimum.
2) No grammatical errors either. Consult your favorite English teacher.
3) No jargon, abbreviations or acronyms that confuse people (I was helping my cousin yesterday and she wanted to use the keyword “OB/GYN,” which is fine since “obstetrics/gynecology” is probably never used, but the more pronounceable and popularly-recognized acronym is), so there has to be an element of practicality to this rule,
4) There really is no reason to capitalize anything on LinkedIn except an acronym. It just looks like you are shouting.
5) Use wit and puns very sparingly and carefully. Your sense of humor may not appeal to others.
But most importantly. don’t hesitate to express yourself in your personal LinkedIn profile in a way that reflects WHY YOU–who you really are, as if you were speaking to the reader.
Write, let it cool, rewrite. Publish it. Tweak it later as you see fit.