Originally posted in what I thought was a more recent thread
Having seen how fast you play (see above: often < 1 sec/move), the most important thing for you now is to give yourself time to think.
Why do you play so fast?
You need to slow down, and @Feijoa has made a good suggestion, above: use the Submit move button. I have another idea that you may find helpful: get into a habit like this for your moves: have a drink (tea, coffee, water, juice, whatever floats your boat) at your side, and when you see your opponent’s move, look at it while taking a sip, using the hand you would move with. Then look where you want to make your move, and imagine the stone there, or enable the Submit move button and make your provisional click. Ask yourself if that is an obvious mistake, and only when you feel it is not, submit your move. It does not have to be a drink; anything that slows you down is good.
But why do you play so fast?