A Few Points
Some of these will probably be controversial among skeptics, but I'd like to hear opinions on such tactics:
Position yourself to their right.
People say "yes" more to people who are thinner than fatter. So lose weight if you need to.
Lean in a little when they are talking about what is important to them.
Get small movements, then escalate over time. (Foot-in-the-Door principle)
To get someone to do something, get them to take an action (physical).
Creating a picture in their minds is not as effective, as an actual experience.
When people say they are 99% sure, they are actually 90% sure.
People overestimate their own certainty levels.
Do some light cold reading to make them comfortable with you.
People do this all the time naturally.
By light cold reading, I mean tell them your general positive or neutral impressions of them.
It's OK to be wrong.
Give them a skeptical compliment as you cold read.
"You don't believe everything you hear, you like to make sure, don't you."
This sets up an expectation that they have questioned whatever supernatural beliefs they may present later. Remind them that they are skeptical people, when they bring those up.