1. Do not be the egg, add a face. For a brand may be logo can work but face wins over a logo any day. See how Zappos CEO uses it – http://twitter.com/ZAPPOS. If you have to use a brand use it at the bottom of the profile.
2. Intelligent tweets – mix of RTs, quotes, links to others etc.
3. Pimping your twitter profile – stay away from words like Guru and expert
4. It is good to be prolific but do not posts 100 retweets within 5 minutes just because you want to increase the number of your tweets.
5. Engage – with community; participate in Follow Fridays, ask questions, answer to @ mentions.
6. Do not see twitter as a chore. See it as something which you do just before or after lunch or during breaks, while waiting at a clients office.
7. Promote – it is key, show your twitter profile in right places. Your email sigs, your business card. You may even make card with only @yourtwitterhandle written on it.
8. Run tweet contests for your brand.
9. Follow back those who follow you. Take a minute to see through their profile and then see do they have content that interests you. If yes, go follow.
10. Once in a while go through DMs.