Could you be a bit more specific.
I am an advit Zerg Gamer and one tip that comes to mind is expand rapidly. Zergs are animals not metal and machine, like Terran and Toss. The Zergs are designed to roam so make mulitiple hatcherys, at least two in the begining of the game.
Utilize the burrow feature, that is an ability no other race has.
I use it to attack my enemy from behind "surprise attack".
Also upgrad the hatchery into a Hive as soon as possibe, this increase the speed of the spawning pool to produce more eggs and it increases the strength of the defense colonies and overall mutaing abilities.