A general rule is to remember that many people won't hesitate to publish something to social media that they would never say to another person face to face. It's important to have discipline when it comes to social media with what you share and how you participate.
First, be careful not to get drawn into arguments. Some people take to social media out of frustration with their own lives. It becomes a place for them to publish provocative statements intended to draw responses and begin arguments.
Second, realize what you post reflects on you as a Christian. If you post on Sunday about your church experience but then post on Monday about an annoying person at work, on Wednesday about another negative opinion about people in the supermarket, and again on the weekend about the great parties you attended (with pictures), what does your feed reflect about your own Christianity?
Christians are to be witnesses in our daily lives to the glory of God (1 Peter 2:9-10). Your witness to others can be damaged by what you post in social media.
Third, ask yourself what your social media profile indicates about you? Are you overly political? A family person? Interested in spiritual things? Argumentative? Social media, although existing online, depicts an actual real presentation of ourselves. As Christians, we must think about what we are presenting to the world about not only ourselves but also about our faith.
Likewise, Peter advises that we should always be ready to give an answer to everyone who asks about our the hope we have, but to do so with gentleness and respect (1 Peter 3:15). We should always express ourselves with grace. It will be our example of respect and "quietness," relative to the "noise" of others, that will be remarkable in our witness in social media.
Use social media, enjoy your interactions, and learn. But practice discipline and consider how you are presenting yourself and your faith through how you participate.