Tone is very important! It’s hard enough to keep it to 140 characters, now imagine trying to convey personality and a consistent tone with so few words. It is possible! And it’s pretty easy to achieve — if it’s authentic. Of course, if you’re cranky until the third cup of coffee it’s pretty difficult to project perkiness first thing in the morning.
What many of the most successful tweeters do is distill their personalities and interests down to a few key themes. Think about your key themes. What do you care about? Who are you trying to reach? What topics do they care about? Stick to them!