Letting the person know what he stand to gain if he can put faith in you. And also presenting the person with evidence of how reliable you product is
Make them realize your item has value to them. Your item must answer a need which they have in order for them to be interested in it on the first place. Your item must provide them more opportunities to profit more than what they bought it for.
By showing them physical structures on ground and how you plan to grow the business and how they investment will be gotten back within a speculated time