Tips for Ranked

I played my 1st 3 games of ranked.. and i lost all 3 of them.. 1st game i got 0/4 early from a SHACO who camped mid!! i was against an Orianna and i was playing Yasuo. SHACO was lvl 4 when they both 2v1 on me. And no it's not that i didn't place a ward.. i did! But luckily we had a Nidalee that never showed :S so we ended up losing the game. The 2nd was less difficult but was lost as well. And the 3rd was from the beginning a none reasonable team because they were fighting in champions pick :S. Can anyone help me with some tips and counter plays and what makes a wise choice in ranked?