Hi CommercialDomains,
Here are some tips for you:
1. Use different passwords on all registrars.
2. Use alphanumeric passwords with special characters such as !@#$%^&*().
3. Turn on domain locking to prevent transfers.
4. Use whois privacy protection (whoisguard etc..) to protect your privacy.
5. Don't access your registrars from public computers, internet cafe's etc..
6. If you receive an email from your registrar, then don't click on the link. Start your web browser separately and type in the registrars main website link.
7. Don't respond to letters (from other companies) you receive in the post asking for your domain name to be renewed.
8. Use a firewall, antivirus, anti-spyware software on your computer at home. Don't just rely on your DSL modems firewall features and don't rely on Windows Firewall as its nowhere near as secure as the commercially available firewalls.
Hope this helps.