I and a bunch of my IRL friends exclusively play ARAM in PH and we did have a conversation about this and came up with:

If you are playing as Shaco or Teemo, please don't hide in the brush all day waiting for your teammate to get someone low, low enough for you to 1 hit with your Blinding Dart or Two-Shiv Poison. Playing against the enemy team is hard enough, but not having you contribute towards the early game worse. Yes, I understand that you have to survive the early game, but so does every single ADC I play with. tl;dr Don't just KS then lulz away, PLZ!1!

If you are in a country that generally has its player base playing in Internet Cafes/PC Bangs. Please, FOR THE LOVE OF GOD! DO NOT PLAY AN ARAM GAME IF YOU HAVE 10MINS LEFT OF YOUR REMAINING TIME. (PH LoL has this problem for a long time and I haven't seen anyone ever getting punished over this.) If this ever happens, try asking in the lobby if anyone have enough time for a single game of ARAM. (I usually ask them if they have 20mins+ of their remaining time) If NOT, then politely ask them to leave.