A domain name should be as short and simple as possible, so that it can be easily remembered and entered on Google searches. A domain name such as annec.no is easy to remember, while for example, jewellery-and-polymerclay-tutorial-heaven.com is completely hopeless with all the words and tying the lines. (which was actually the name of my first website, I have to blush admit.)
It should also preferably be related to your name, service or company name.
When you order a domain, you can usually enter the name you want, and then you'll see a list that shows whether it's free or not. If it is not available, try different variations of the name you want.
For example, I want the domain annec.no. It's busy, so I try with annec-design.no, annecdesign.no, etc.
Avoid the use of e,ø and to in domain names, as it can lead to complications.