It helps to read a single example of a testimonial closely rather than skim thirty. This page takes one apart: what each sentence is doing, why the order works, and which question produced it. The point is not to copy the words, because a testimonial that is not what the customer said is worthless and, under the FTC's rule, unlawful, but to see how an ordinary answer to three plain questions becomes something usable.
The sentence that sets the scene
'We had three people quoting by hand and no two quotes looked alike.' It is the answer to what the situation was before. Without it the rest is praise floating in the air. It is also the sentence most customers skip unless the question asks for it, which is why the before question comes first in every sheet on this site.
The sentence that says what changed
'Now the quote goes out the same afternoon.' Specific, checkable, no adjectives. It came from asking what is different now rather than what they think of the product. Notice what is missing: no adjectives about the company, no mention of the product name, nothing a competitor could have written about themselves.
The line that carries the credit
Name, role, company. An unattributed quote is worth very little; a first name and a city is the minimum, and a role plus a company is what makes a reader believe it. Collect all three when the testimonial arrives rather than chasing them later, because the person who gave you the quote may have changed job by the time the page is built.
Questions people ask about example of a testimonial
Is a short testimonial too short?
Two good sentences beat a paragraph. Length is not credibility.
Should I include the customer's photograph?
If they agree, yes: it lifts believability more than the words around it. Keep the permission with it.
Can I anonymise one?
Yes, when the customer's employer will not allow attribution. Say what kind of business it is and why it is anonymous.