While high school definitely isn't everyone's best four years, there are a few things you need to do before your senior year becomes a part of the past.
Take a day trip with your friends
Senior year gives most of us a little leniency to go out with our friends more often, and it's important to take advantage of that.
Go to the school games
Even if your school sucks at sports, attend a game or two and give in to the school spirit.
Talk to your teachers
Teachers, the good and the bad ones, have a large part in shaping your high school experience. Teachers are more open to their seniors as the school year progresses, and you'll probably have the opportunity to get to communicate with them on a deeper level. It's always interesting to get to know your teacher as a person.
Talk to the people you never really interacted with before, too
Instead of sticking with your same old friend group for the rest of the year, branch out and talk to people you never had the change to interact with before. You never know who you might make a friend out of.
Go through your old high school yearbooks/mementos
Going through my old yearbooks and pictures throughout the years always made me a little nostalgic. You get to see yourself grow and are able to look back at all the memories you made from the time you were a freshman to now.
Skip class
You've got to do this at least once before you graduate. The penalty shouldn't be too severe, either (that is, if you get caught).
Attend every senior event
Most high schools do their best to make senior year a memorable time for the students, so skipping a senior event that essentially takes you out of class is pointless.
Don't you dare skip prom
It's the last time you'll see everyone from your grade in the same room together and actually be able to talk to most of them (graduation is too hectic).
Go to school the day before graduation
Your last full day of school is something you're going to want to be there for. It's the last time you will attend class, see familiar faces in the hall, eat gross cafeteria food, and race to the parking lot in order to beat traffic.