Benefits over features
Customers don't care that your paint is 'silicone-based'; they care that it 'lasts ten years without peeling'. Translate every feature into what it does for them.
A feature is what it is ('silicone-based'); a benefit is what it does for them ('lasts ten years without peeling'). Sell the benefit.
Write to one person
Picture a single ideal customer and write to them, not a crowd. 'You' beats 'our valued clients' every time.
Use their words
Read how customers describe their problem — in reviews, emails, WhatsApp — and use those exact words. It makes them feel understood.