A list of precautions or measures has been compiled, I found is good to share so sharing here.

1. Not using it on public computer, ie. like cyber cafe.
2. Not using it on computer of non-trusted people..(not trusted, may have keylogger installed)
3. Never ever use it on non-geek's computer as mostly they are filled up with loads of trojan and virus which may steal your informations.
4. Always making sure that company which is going to charge my credit card is a genuine and reputated.
5. Not using my usual browser for e-commerce as it might have some trojan hidden , entering while I am doing day to day surfing. (Here I use Opera for my e-commerce related stuff only)
6. Never use CC on some small ISP, they may have someone spying on your data or may gain access to your computer's data as they are less (ie. small ISP) concerned about privacy of their users.
7. Regular clean your browser's cache so that if someone manage to hide in there .. can't affect you.
8. For company where you don't trust them 100% , try using service as my bank provide ie. temporary CC which expires only after first use.
9. Ofcourse Install good antivirus software and keep it updated and also do regular computer scan.
10. Never -ever use CC if you are on some proxy for internet connectivity, though transfer of data is encrypted but chances are high of session highjacking etc.
11. Always make sure that you are accessing your netbanking or CC payment site using right URL, ie . someone is not doing URL spoofing. If you doubt upon it then just ping the URL of the company from different location and if IP is same then its original. Here different location means : using tools like dns-stuff.com
12. If suspect something unusual about your transaction then immediately stop it, check for problem, make sure it is not some serious one or dangerous and then only move further.
13. Do not install application from untrusted sites, warez sites, they mostly contains keylogger, trojan etc. DO NOT USE PIRATED SOFTWARE. They may contain custom made malicious scrips which cant be detected by Antivirus software.
14. Never Ever give your credit card details on website who uses non secure http connection ie. if site is having address url as : https then its ok and it is only "http://" then do not use there.