Nearly all the companies I know that sell to other businesses, rely on repeat transactions from the same customers to stay afloat. Repeat transactions only occur when there is mutual trust. You are never going to be successful in your B2B sales without fostering strong trust with your customers.
It goes without saying, but the last thing you should do is to say, "Trust me!". I guarantee that statement will cause the opposite effect :)
Instead you should focus on building your empathy for your customer's challenges and figure out how you can help them make progress.
When the customer knows that you are completely open with them and have their back, it will be more likely they will work more collaboratively with you and help you to sell into their organisation.
Future posts will open up this conversation on building greater mutual trust with your customers.