In an interview, the main piece of advice is “be honest”. Well, obviously, if you are sloppy and disorganize with your work, you will not say that…
The key here is to find weaknesses (true or not), which can be converted into strengths or advantages for the job you are applying to.
Let’s say you are going to investment banking and you are asked this question. You could answer, “I have trouble respecting long-term deadlines. I always start working when I am under pressure, and when I start, I can only stop when I’m done”.
This can be a weakness for some job. Let’s say you had a previous experience where you had to plan your work in advance and where people were leaving at 5pm every day: being unable to start working a long time in advance would have been a serious problem. On the other hand, for investment banks, it would be the perfect profile: working under pressure, for short deadlines and late at night. Always back up your stories with examples (previous work experience or others).