Play at late night (midnight and so on) or play before lunch (9am-noon). Basically you are tying to hit people that are a bit older (college students) and will less likely rage. Also people that play late at night normally play more often and such his ability is slightly higher. While I was in college I would play mostly around 3am and I felt much better about playing league, i was sorta an insomniac so I would play 3-4 nights a week.
Now that I have a full time job is harder to put all nighters and still be productive enough to not get fired so I can only play 1-2 nights a week.
The downside is you might also encounter drunk players, high players and drowsy players that will unintentionally play bad, good thing is they usually black out after a game or two so if you play 5 games during a night most likely in 1 will encounter this players.