1. Decide what you're going to tweet about. It's easier to build a following on Twitter when people know what you will be tweeting about. If you're all over the place, it'll be harder. This does not mean if you tweet about marketing, you can't tweet about your favorite NBA team. Just try to be consistent. For example, I tweet 90% about marketing, technology and networking. 10% is whatever I'm in the mood to tweet about.
2. Remember that everything is public. Think before you tweet. People have lost their jobs for the things they have tweeted about. A PR executive with some racists tweets is the latest casualty.
3. Put up a professional profile picture. Just like LinkedIn, if you're using Twitter to expand your network, it can help to have a professional picture. At least put some kind of picture up. No one wants to see the Twitter egg.
4. Fill out the description. This is your chance to let people know what you'll be tweeting about. I recommend you link to your LinkedIn profile, blog or personal website in the description.
5. Post consistently. If you never post, many people will eventually stop following you.
6. Follow people. Follow anyone or anything that interests you. Follow companies you are interested in or people you admire.
7. Favorite tweets. This is a simple way to let people know you like what they are sharing. Twitter notifies you when someone favorites your tweet. This is also a great way to get someone to follow you back.
9. Respond to tweets. The great thing about Twitter is most people on it are the sort of people that want to have conversations with the Twitter community. Comment on posts, or respond to questions. You'll be surprised who might respond back.
10. Be yourself. The more authentic the better.
Twitter can be a valuable tool as you navigate your career. Have fun with it and find what aspect of Twitter creates the most value for you personally. Good luck and happy tweeting.