"Not everyone cracks jokes all day long. But a light touch from time to time lowers a reader's guard and opens her to your ideas."
What about him?
Why do people write, and put him/her instead of their?
Even this article above, you said "her" which offends me, as I was reading it relating it to me, and I'm not a her. You could have said;
"lowers a reader's guard and opens them to your ideas."
Keep your writing as gender free as possible.
Him/Her = their/them/they
Writing should be about ideas, not what's between someones legs. (unless the writing is directly and specifically about a certain person)