How do you win match through botlane in gold elo ?

Hey so I started to play duo on my smurf with friend, but somehow i can't keep winning in gold. Our winrate is 48% but we keep winning like 8/10 botlane matchups. We usually play Tristana and cait + enchanter like nami or janna but in teamfights enemy always crush us. I had been promoting friends to plat as support for seasons but somehow it's not working this time. any tips how to improve ? We have good macro. So plz no tips like better wave management.