What the site should show
This is what separates a serious tradesperson from a random ad.
What you actually do
"All plumbing work" says little. "New bathrooms, water heaters, heat pumps and leaks" says more, and is what people search for.
Where you work
Which municipalities and areas you take jobs in. The customer does not want to call only to find out you do not go there.
Jobs you have done
Before and after photos from your own projects, ideally with a sentence about what was done.
Approvals and certificates
Master craftsman certificate, trade certificate, approved wet-room company, registration in the electrical contractors register. Whatever you have should be shown.
Who you are
A photo of the people and the company van does more than you think. The customer is going to let you in.
Org. number and insurance
The organisation number at the bottom of the page, and that you have liability insurance. Small things that build trust.