Interest reduction strategy

I bought a > 2M house in Bay Area at 6.8% interest and 40% down. Obviously the total cost of mortgage over the course of 30 years will be really high. I have cash to pay off the mortgage but I would rather stay liquid and also leave room for renovations and repairs over there years. What’s the best strategy to minimize my interest payments over the next 10-15 years. Some options I’m considering:

(i’m 41M and we are just about 48% debt to income on take home pay)

  1. Payoff entirely (less desired but will consider)
  2. Pay a little extra towards principle every month
  3. Pay a lump sum end of every year:
  4. Do nothing and keep the rest invested (in index fund ETF VTI currently)