Reassuring Passenger............

You can buy a belt-style device which you wear over your jacket. It has grab handles on it for your passenger.

 

Just don’t pull a wheelie on them
I find explaing how the bike reacts , what is expected of them and sorting some signals like stop soon and stop this fire breathing demon from hell right now works well.

 

I use a belt similar to that for my grandchildren when they come for a ride with me. Usually grow out of it fairly quickly, as they soon learn to hang on with their knees, and to lean in the appropriate direction to counter cornering and acceleration forces !
But it's certainly a major benefit for early rides to introduce a novice to bike riding as a pillion !
It certainly gave two of my Granddaughters more confidence, and they definitely had more fun because they didn't worry about falls, and a good talk about what to do and how to stop the ride if they didn't want to continue gives them a greater sense of having control of things !!