Use Creep Tumor as often as u can! It is one of the most handy trait of all!
Its givin' sight, slowin' enemies, give u move speed, etc.
Go in 'forests' often and use Ur tumor as a ward to see and slow enemy heroes!
Always use Tumor next to the lane u r on, to see the gankers come in time!
After lvl 10 u can go home for mana and hp every time! If u r under 50% hp go home!
If u see gankers coming put a Worm right front of u and go!
Keep a Nydus Worm at home always. It doesnt matter where u put the others (i still suggest bushes) becouse u can put them everywhere after u r doing the 'warding' right.
This build is pusher and hero killer as well.
Try to keep Hunter Killers for low health assassin heroes in teamfights, however they are effective for pushing as well.
Baneling Barrage is really effective against towers if u just send them next to the lanecreeps straight to the gate. Its effective against ranged assassin heroes, who are to far to reach. Just send them the gift. at least there will be another enemy character. ;)

NEVER FORGET TO USE TUMOR!!!!! Its really handy for the whole of your team!
And sight is so so so important in team fights!! Ward bosses too!