A domain name should be as short and simple as possible so that it can be easily remembered and typed into Google search. A domain name such as annec.no is easy to remember, while e.g. jewellery-and-polymerclay-tutorial-heaven.com is completely hopeless with all the words and binding lines. (which was actually the name of my first website, I have to blushing admit.)
It should also preferably be related to your name, service or company name.
When ordering a domain, you can usually enter the name you want, and then you will see a list showing whether it is available or not. If it is not available, you can try different variations of the name you want.
For example, I want the domain annec.no. It's busy, so then I try with annec-design.no, annecdesign.no etc.
Avoid using æ, ø and å in domain names, as this can lead to complications.