Respect you home. Keep it clean and in a sanitary condition. If you have pets, pick up after them.
Failure to do so is often considered a lease violation and can be cause for eviction.
Also, when it comes time for your move out, it's likely that not only will you not get your security deposit back, but you will owe money for cleaning and repair.
Take the time to do the little things now so that they will not become big things later.