Domains are cheap, which encourages treating the decision lightly. It is one of the few choices in a small business that is genuinely difficult to undo, because everything ends up pointing at it. Email addresses, printed material, reviews, links from other sites.
The Telephone Test
Say it out loud to someone who has never seen it written, and have them type it.
Hyphens fail this immediately. So do words with two spellings, numbers that could be digits or words, and anything where a letter doubles across a word boundary. If you find yourself saying "all one word, no hyphen, that's with a zero", the name is costing you customers every time it is spoken.
Keywords Are Not The Win They Were
Exact match domains stuffed with keywords carried real weight fifteen years ago. Search engines discount them heavily now, and they age badly. A name describing precisely what you sell today is a constraint when you sell something adjacent in five years.
A short, memorable brand name beats a long descriptive one for almost every small business.
.co.uk Or.com
If you serve UK customers. co.uk is not a downgrade. It signals where you are, which is exactly what a local customer is looking for, and the name you want is far more likely to be available.
Buy both if you can afford it and redirect one, mainly to stop somebody else running something at the near-identical address later.
Practical Things People Skip
Register it in your own name with your own contact email, not your designer's. Set it to auto renew. Note the renewal date somewhere you will see it. Keep the registrar login separate from your hosting login.
Expired domains get picked up quickly, and buying yours back from someone who noticed is expensive and undignified. The whole failure mode is prevented by a diary entry.
