Haste is an attribute in the game which affects your auto-attacking speed, your global cooldown time, your automator speed and the base cooldowns of all skills.
Your base haste is 100%.
1. Expand your skill tree. You will find 1.05x and 1.178x haste there. (Permanent)
2. Buy gears which have +5% Haste. Note that this only lasts for the rest of the world.
See skills for the whole list of them.