What do you think are the most important qualities for someone to excel?

Communication skills are vital, effective and strong communication skills come with experience the more people you deal with the better communicator you will be, also problem solving skills , employers highly valuable people who can fix issues, resolve issues, that have positive attitude, look for solutions instead of discussing problems.
Another very important skill is being initiative by doing things without being told, spotting and taking advantage of opportunities, for this you can set yourself a goal to implement and come up with an initiative every quarter that has good impact on people day to day job, that will make their life easier, or maybe save your company some money .. or other ideas.
Last but not least, you really need to be able to work well with others, to be a good team player, to be respectful for everyone's opinion, to help others achieve their goals and objectives.