As is true in any discipline, historians have a range of personalities and skill-sets. However, there are some skills historians typically must have to engage in the discipline and enjoy a successful career.
To become a historian.....
You must be able to read and write well.
To become a historian, you will do a lot of reading and writing. Graduate school alone will require you to read and write hundreds upon hundreds (dare I say thousands?) of books, articles, and papers. Not to mention that the base of any good history-based career requires professionals to research (read and write) on an ongoing basis.
You must be able to think critically.
History is not a fixed subject filled with facts and perfect data. In fact, history is often filled with lies, rumors, and questionable data. Historians therefore, in both their academic and professional settings, must be able to think critically about the information in front of them; they must consider where it came from and what to do with it. Historians are ultimately translators of events past, and to decipher the meaning of events, circumstances, and occurrences requires an ability to think critically about everything from evidence and opinions to facts and outcomes. In addition to this, you must be observant. You must be able to spot trends, aberrations, and patterns.
You must be flexible and patient.
As researchers and educators, historians must understand that revealing and sharing the past requires exploration and getting lost. They must be able to change their minds, move in new directions, question accepted truths, and keep their minds open. They must be willing to move where the data takes them and to respect the amount of time and consideration doing so requires.
You must be willing to travel.
Most historians need to be willing to travel to the places they study. Historians depend upon primary and secondary sources, and many of each can only be found in the region from whence they came. Only historians who live where they work can hope to avoid traveling, though even they travel to share their work with others.
You must be knowledgeable of other disciplines and subjects.
History is a subject that spans disciplines. Historians study events, circumstances, and occurrences that span social, economic, and political themes. It is useful, therefore, to become a historian to be knowledgeable and skilled in a discipline related to their field. Many historians are well-read in disciplines such as sociology, anthropology, economics, political science, literature, and others, and historians use that knowledge to better understand their field of history.
You must understand how to research.
Historians are researchers by nature. Their discipline depends on the successful discovery and analysis of events past. They therefore must understand the social nature of research; the difference between primary and secondary sources; how to discern the tone, nature, quality, and meaning of sources; and how to add their own voice to the historical record in a meaningful and trustworthy way.
You must engage in the research process.
First and foremost, historians must respect the historical record. Then they must strive to be a productive, honest, and relevant contributor to it. They must conduct strong research, write about their findings, and share their findings with other. Then they must invite others to respond and to ultimately grow what we know and understand about a given subject.
You must be able to discern fact from fiction.
Both fact and “fiction” are included in history and historians must be able to discern between the two. Historians are story-tellers, and the relevance, trustworthiness, and importance of the stories they tell depend upon their ability to present evidence in a historically accurate way. Doing so requires a desire and ability to discern, both for themselves and their consumers, the meaning (fact or fiction and the relevance and importance of each) of their sources.
You could benefit from knowing more than one language.
Historians don’t have to know a second language, but it sure is useful come time to read sources in Latin or interview people in Spanish, Sesotho, or Japanese. Most historians work in locations, eras, and subjects that require, at minimum, a basic knowledge of another language or dialect to fully understand the meaning of various sources and the context within which the history resides.
You could benefit from knowing how to socialize and communicate with people.
While some historians stay buried in books and other inanimate resources, most interact with people while conducting research. Historians who can make connections, develop relationships, and communicate with different types of people will have an easier time in their careers, most of which require historians to find and interpret data through the help of other human beings.
While possessing these qualities is not necessarily a requirement of graduate students of history or practicing historians, they may help to enhance one's enjoyment of the study of history. However; if you think that you possess these qualities and you have an interest in earning a graduate degree in the subject, pursuing education and training to become a historian may be a great choice for you!