The social networks are used mostly for the fun of it, a lot of people around the world lose countless hours every day exchanging information and jokes, watching pictures and videos, and, why not, tweeting. The social networks are one of the best places in the virtual world to promote (anything you want to promote), but you should be aware about the specific rules and the world every network is creating. Some things are general to all of them, but some are particular and if you don't take them into consideration will be wasting a lot of time and energy for (almost) nothing.
The general ideas about promoting yourself and your clients or products on Twitter.
Define your goals
Too obvious, isn't it? Maybe this is the reason how many people (including the ones involved in promoting their business) fail in defining some clear goals (or not at all in some cases) when are making waves in social media. The allure of social networks (not only Twitter) is strong and for a lot of internet users it's tempting to look around to their competitors' online marketing and to imitate their actions without fully understand what's at stake.
So define exactly what you hope to gain from your promotion, you can only design it better when you know what you are doing. The goals depend of what you are selling/offering as services. I can not give detailed information as long I don't know what you are promoting, but in order to get the most out of twitter you must have a working plan.
Exploit your medium
For Twitter to be effective you must send a clear and loud message. So tweet... and tweet again. Without frequent updates you are out of mind, you can grow stagnant. There is not limit to the number of times you can tweet, but you must interact with the other users to make yourself an audience. This means you can not only tweet official information or titles with links to your articles, you also have to talk with others.
Also, the social networks (for example Twitter and Facebok as two of the most well known) have enormous potential to spread promotion at viral rates. It's up to you to use the tools they are offering and to take full advantage of them.
Set metrics
Once you have defined your goals you must set metrics for measuring your achievements. It's not enough to set the plans and, leter, to tweet 1,000 times if there is nobody following you and all your efforts does not generate traffic to your site or clients to your products and/or services. Make sure you have a solid grasp on all your figures before launching the campaign and find out how you can isolate your social media traffic from the rest of the traffic and to put the results in a specific context.
Evaluate and adjust
Don't expect that your campaign would be very succesful from the beginning. It may happen from time to time, but most of them will become succesful only after a period of hard work and perseverance. Learn from your mistakes and the mistakes of others (and there are a lot of them), assess the strengths and weakness of your campaign and adjust your fututre campaigns.
The specific ideas, dedicated for Twitter and it's environment.
One of the most complex Twitter features is the hasthag, a toping that starts with the hash symbol # in order to identify it. It's very important to mention that the name of the hashtag is always formed from one word, even the full name contains several words put together. A very used hashtag is #followfriday (or #ff as short), the users recommend people to folow others every friday.
Hashtag is a great tool to organize conferences and events and to help people follow discussions or/and organize themselves: it's very easy to find a topic in the thousands of tweets written every hour, it's more likely that the topic you follow and participate will appear in Twitter's Trending Topics.
Identify hashtags
As I wrote earlier, you must interact with the people on Twirtter in order to get an audience. Using hashtag and adding an opinion to them can easily help you to communicate with others. Trend are very important in Twitter world, so identify the most common hashtags in order to get the most out of Twitter. You can also try to create new ones, but be specific to a clear subject.
The most important hashtags are the one similar to your object of activity. The public that follows them can become your audience, your clients.
Track hashtags
In order to find out people are saying about one thing or another use the tools available on internet that do that. It's easy to search them on yahoo or google (for example).
Use hashtags
As every other things in the world, hashtags have some rules. The primary one is: don't overuse them. Don't put a hashtag to every tweet or you'll risk to fragment the conversation. It seems spammy.
The other important rule: put a context to every hashtag you use. That can be an explanation or a text to the subject of the hasthag. If you are making a hashtag make it so clear that everyone understands it.
Organize hastags
This subject is about conferences and events as they rely the most on hashtags, it's almost a standard to track a conversation regarding speakers and afterparties using a hashtag.
If you are organizing an event there are a few thing you should do about this tool: choose a single hashtag, constanly remind the attendees about it and provide a website widget (it's an easy conversation tracker on one's website).