1)Bring your own bag when you go food and grocery shopping, it reduces the need for polythene bags.
2)Carry your own water bottle so that you don't have to buy disposable water bottles.
3)Say no to plastic straws, switch to metal straws and make it a point to carey ut with you at all times or else just drink from the cup.
4)Zero waste movement, its not possible to turn zero waste in a finger snap, but being a little plastic conscious can go a long way.