Ask nicely
It doesn't take much time in the company of books by Dale Carnegie, Robert Cialdini or or Rory Sutherland to cotton onto the fact that how you say something can be be just as important as what you say. Nor is this exactly news: How to Win Friends and Influence People was published 85 years ago.
But it does not take much time in the company of of a modern commercial contract to see that learned legal eagle friends have proven stoutly resistant to its charms. Legal drafting is habitually fastidious over particularised and and logical at the expense of being what Sutherland calls psycho-logical.
As we move into the information age the need for clarity simplicity and brevity will be imperative like it never has been before, so perhaps this is the moment to score a commercial advantage by doing things differently.
A simple example: say you want to ensure all customers in your shop wear face masks.
Now your objective here is not simply to ensure that no barefaced customers comes in your shop. That is not even your dominant objective. You could achieve that by locking the door. what do you want is as many masked people as possible to come in your shop, and for them to be as as well disposed as possible towards purchasing from you, when they do.
If no-one comes in your shop there is no point having a door, or for that matter a shop, at all.
“all person's entering this store must wear a face mask”