Merriam-Webster Dictionary defines citizenship as the quality of an individual's response to being a member of a community.
If I were to define it i would say that citizenship is the responsibility to be a productive and intelligent member of society.
To be a good citizen you need to fulfill you duties as a citizen. This means you need to take part in government by voting. To do this efficiently you need to keep yourself up to date on the matters at hand. If there are multiple people running for an office, then educuate yourself on their stances on certain important issues and find out what their platform is. You need to always be well involved in what is going on around you. This doesn't just translate in being active in things like government though. You also should be active in your community.
Note that I said "YOUR community." You live there and do your daily routine there so you should care about the area that you live. You should take responsibility for that and take care of your community. This could be shown in a number of ways. For example one of these ways could be by taking part in an event that raises money for some sort of organization in your community like a homeless shelter. Kind of like hmmm..... a philanthropy if you will. Another way you can take care of your community is by doing community service. This could be anything from volunteering around your community helping others or picking up trash on the side of the road.
The most important thing is that we need to SET THE EXAMPLE so that other people get involved. I'm sure all of this reminded you all of something..... oh yes that's right. Greek Life. All of our houses talk about how much of an impact we all have on our community through philanthropy and community service activities. This is not enough. Yes it's awesome to have all of the greeks get so excited about helping the community but the most important aspect of citizenship, to me at least, is spawning the desire to make a difference in others. That's what being a citizen is all about. Making an impact on not just the community but getting others excited about making an impact as well