Stop Talking
Stop talking too much. Answer interview questions concisely.
Let's face it, interviewing can be stressful. For many, this creates nervousness which leads to talking too much during the interview.
You have to remember that every interviewer has an agenda. Their goal is to get as many questions answered as possible. They need to collect as much data as possible in order to make a good hiring decision. Talking too much prevents this from happening.
It's a red flag for an interviewer when a candidate is talking way too much. They come to the conclusion that nothing will ever get done if they hire the candidate.
The best way to eliminate nervousness is through preparation. I always recommend doing mock interviews before your actual interview. Grab a friend and practice verbalizing answers using the STAR + L methodology.