Put things out into the world that prove you know what you're doing.
@visualizevalue published 500~ images before asking anyone to part with their hard earned cash.

Based on the reputation you've built, offer products and services that intersect with the interests of your audience and your specific abilities.
For @visualizevalue this is $20k+ consulting engagements through $19 digital products.

As customers use your products and hire you for your services, ask them to share feedback on their experience.
For @visualizevalue, this is a follow-up sequence built into the distribution of digital products.

Word of mouth is useful, but putting the growth of your business entirely in the hands of people that have their own lives to worry about is not a particularly strong strategy.
Put your work out there until people believe in your ability enough to pay you to help them.
To dig deeper, read the reviews on this page and hit buy if you're convinced:
shop.visualizevalue.com/products/build…