Many people are very proud of all the tasks they perform(ed) at work. When I do job transition workshops, attendees talk about wearing multiple hats, doing tasks outside their job description, and being of value in many ways to their company. All this is important and contributes to a persons work-esteem, however in an interview (and in a resume) focus on what is of value to the company that is considering hiring you.
Candidates try to load too many things into an interview and they lose focus. Candidates also tend to get too detailed thinking that the larger the volume of things they talk about the more persuasive they are. Too many details and too many tasks tend to confuse the interviewer and once confused they get turned off.
As I often state, the interview is a sales call. All good sales calls are targeted towards solving the buyers problem. Determine the problem and focus on it like a laser.
What specifically are you being hired to do. Look below the surface. A person being hired to do collections for a company is not just collecting money they are solving the problem of reducing accounts receivable and improving profits. Anything talked about in the interview should have the ultimate goal of reducing accounts receivable and improving profits. Even a question related to getting along with co-workers or a supervisor should be answered in the context of how does the answer relate to reducing accounts receivable and improving profits.
By focusing on being the solution to a problem, your answers will be more targeted and less rambling. As each question is asked, think to yourself how does this relate to solving the ultimate problem. Then leave out anything that does not contribute to the solution. Also, if you are not asked a question that elicits a task or skill you have that contributes to solveing the problem, be sure to bring that out yourself.
To prepare for your interview first define the problem the job solves and then list all the things you can do that contributes to solving that problem. Bring the list with you to the interview and make sure you cover each thing on the list.
People only buy what they need and only hire you for the things you can do to solve the problem. Focus in on the problem, keep it simple and be persuasive.