When opening sales, there are specific words you should be cautious of in other not to send your customer(s) running.

This article brings to you 8 words you should avoid in sales and a better way to say it. Check here https://www.offerservice.com/forums/forums-details/8-words-to-avoid-in-your-sales-offer-service

You don't really have to study it yourself. The psychology of the client is very different from the psychology of the average person as you imagine him to be. If I were you, I would turn this work over to people who really know what the client wants. I personally used this service https://newmediaservices.com.au/5-best-practices-to-improve-customer-satisfaction/ and they helped me quite seriously. So do not waste your energy and time.