Finding people and following them seems to be the most popular method. Remember that more people you follow, more followers you get. Many of your followers will stop following you if all you do is following others and not providing any value. Following to many people might ruin your following/followers ratio and will make people to think you are a scammer or a bot which will result in not getting any followers.
Unless you are a celebrity or famous on internet for whatever reason, you will have to work a bit to get more twitter followers .
Tip 1- Follow to be followed, but do it slowly. Don't follow 500 people a day. 1-1 is perfect for your following /followers ratio. If you follow 100 people and have 100 followers do not try to follow another 100 people in a day, rather in a week.
Tip 2- Share what you know, what you thing might be interesting and provide value.
Share links to interesting things on the web.
Have conversations.
Tip 3- Filling a bio and picture are a must. People get turned away if there's nothing to see in your Twitter profile. Add a picture of you and write a few things about yourself. If people do not know anything about you, they will not talk to you.
Tip 4- Create a website or start blogging. People will be able to know you better if you provide them with a link to your website or a blog. You personality is expressed better on your blog than in the bio in Twitter profile.
Tip 5- Always reply to your followers and re-tweet valuable information. When your followers do the same to you, your name will be visible to their followers.
Tip 6- Become involved in a Twitter party. Always check if there is a Twitter meetup in your area and make sure that you participate. It is a great opportunity to get new followers and meet new people to follow.
Tip 7- Share your Twitter username in as many places as possible and make sure you get listed in Twitter directories.
Tip 8- Just be yourself and be unique. Express your feelings, speak openly. An interesting opinion will get retweeted and will make your name appear to others. Show your personality by changing colors and personalizing your profile.
Tip 9- Tweet regularly. Do not feel like you have to tweet 24/7, but try to do it every day. People will stop following you if your profile is not updated often.
Tip 10- Get all of the above balanced. Make sure you do not talk only about yourself, as it gets boring after a while and you will start losing followers. Good idea is to post 1-2 out of 10 messages about you and the rest to provide value to your followers.
