Classic How do you "pick" stats?

Im in the end game with my DK (well sort of, my ilvl is 413). I'm and unholy dk that needs haste. But all i am getting is items with mastery. Since it's all random drops , i have almost 60% mastery and 14% haste. I always read that you should try this build and go for a specific stat, but how do you do that when it's always random? Is there anything i can do to try and get things with haste? via /r/wow https://ift.tt/2Y1gU59