ETF or Mutual Funds ?

Hi, I am in dilemma in choosing which one to start investing in, Mutual funds or ETF. I have seen many mutual funds have increased their TER and ETF do not have such added charges but I am not sure which ones to put my money into every month and when the market is down!!! I have been investing in couple of MF’s spread from large mid cap and small cap with some flexi cap too. Looking forward to reading your inputs and analysis.