1st item you must get is vampiric scepter if they are good get berserker greaves if not just save up for bilgewater cutlass then boots.then after buy hextech gunblade. Once you those items get malady then nashors tooth by then the game should be finished if not buyphantom dancer and sword of divine.

just like any other build you plant shrooms eerywhere on map for advantage so you know wats going on the come in reall handy if you have a lane of shrooms and getting chased weave them though and you might be able to kill them depending on who they are and health.If you are vvering sivir dont be affraid to show whos boss but just keep ya distance have move quick on alot of the time and be ready for ganks. At the start just try to get to lvl2 as quick as you can then take big hits and leave them with poison and should be able to get a kill and just try to rely on that till lvl5. This is my first build so be nice plox :) i hope this build help.