The queen is a good early unit but requires lots of gas. With the economy you have early in the game, you can easily make about 3 to 6 queens. A 50 minerals and 150 gas unit, the queen flies very fast and can survive a few hits from anti-air towers. Most useful against the terran and protoss, the queen's abilities pose a great help for the hive cluster.

The parasite is a good scout, especially the in the workers since your opponent rarely bothers scanning the many workers. The critters sometimes are good to have parasite on.

Ensnare should be used in tightly packed units before you attack or the attack units. Ensnare makes them slow pokes and an easy target for your raging swarm. Ensnare makes a squad of zealots or marines a match against a pack of hydralisks and zerglings.

Spawn broodling, the ability that make the queens great assassins. Best used for siege tanks, templars, goliaths and dragoons. Workers busy mining should also be spawned, your opponent might not even notice the broodlings killing his workers. A couple of queens or more can cast a few spawn broodling on the enemy units on guard and run. This hit and run tactic is an effective means of weakening your enemy's defenses and at the same time, making him waste resources building anti-queen structures and units.