Last hit minions to gain more cash,try to play offensively if your oppenent isnt defensive, like standing there waiting for EXP instead of hitting minions, thats the time you fear your oppenent and sheild their skills and then use duskbringer to chase your enemy champion.

When you lane at bot.If you lane with a AD champion try to tell him when you both should kill someone then only you can get kills,but you need to focuz on one champion or both of you will die in either one of enemies's hands.If you lane with a support try to play safely unless you got an supported like taric who can stun people then you can kill either of the eneimies.