At this stage, you are usually better off reinforcing a few high-value basics than chasing new exotic tips. Focus on clean structure, calm communication, solid math, and strong synthesis.
For BCG specifically, it also helps to stay flexible. Candidates sometimes over-script their casing and then struggle when the conversation becomes more interactive or the interviewer pushes in a different direction.
So your best last-mile prep is usually consistency. You want the fundamentals to feel reliable enough that nerves do not knock them loose on the day.