Make sure your email client is set up to display your name and email address correctly. Use a meaningful name for yourself, e.g. "Patrick O'Conner" or "ABC Windows". Do not use non-specific names or names which won't mean anything to some people, e.g. "Buddy" or "The Girls".
Most people tend to want to go for a .com, but getting the domain name you really want maybe more difficult as many .com's have already been registered. Going for a country specific domain registration will mean you have a better chance of getting what you want and it immediately tells others where you are based.