There are a couple of things that you can do during your time in college or after college that may negatively impact your chances of getting medical school.
Do not try to act like someone you are not. It is really easy to tell when someone is not comfortable in their own skin. It is difficult to meet people who have gotten into medical school already and not want to copy their style at your interviews. Just remember, you were given an interview because they liked you enough. Don’t ruin your chance to impress them by acting like someone different from who you are on your application.
Also, if you go to the school the night before or ending up staying the night after, make sure that you do not get stuck in the party scene at any point. Some students feel like it is okay to go out with the medical students the night after an interview but something you may not know is that usually there are medical students on the admissions committee. I would not recommend using this time to socially explore the school you are interviewing, you can make a second trip to evaluate that if necessary.
I know a couple of premed students who were my same year and decided that they wanted to take a whole summer or longer to study for the MCAT and this was the reason they were delaying applying. First piece of advice, try not to give yourself too much time for the MCAT because you will get lazy. Second piece of advice, if you are delaying the application process, you should be doing something during that year besides just sitting around studying for the MCAT. Schools will ask you what you did during your year off and you better have a good answer which does not include watching TV or just studying for the MCAT.
Don’t get me wrong, it is okay to take a year off to give yourself time to study for the MCAT but just make sure you are doing other activities also. These activities do not necessarily have to be related to medicine, it could be doing research, writing for a journal, volunteering, working, etc.
Don’t try and list every little thing you did in college. Basically what I mean is don’t try to “fluff” up your applications just to seem like you did a lot in college.