Just because I am in bronze does not mean I cannot give good advice.

Here are a few things I've learned.

1. ADC's are very useful to have on your team. Because they are so squishy, the other team will target them. They make excellent bait. Hide behind your ADC's and wait until the other team blows all their cooldowns on your adc. Then engage.

2. Some champions are very effective at cleaning up after a fight. Take malphite, for example. His ultimate does like 300 damage (!) and has a very long range. So you can guarantee that that pesky support doesn't leave the fight alive after everything is said and done. Also, his ult is a very strong escape tool, so if it looks like your team is taking a lot of damage, just ult away from the fight (Dyrus was my inspiration in this regard).

3. The team with more damage wins. So you want to build as much damage as possible, especially on supports. Don't buy an early sightstone. In fact, don't buy one at all. You might need to take some of your carry's farm for you to rush that Deathcap.

4. In laning phase, whoever's wave is most pushed is basically winning. Push your wave as hard as you can from the very start of laning phase. Use all skills off cooldown until you are out of mana. For example, you can tell a good nasus from a bad nasus based on how pushed his lane is. Is he at the other player's tower? That is diamond material.

5. Relatedly, if you are jungle, you might need to help your laners push their waves. Often times, top laners will be stuck with the minion wave just in front of their tower, which basically means that they are stuck losing the lane. I've helped many a Nasus by hitting enough of those minions so that the wave pushes back to winning territory.

6. People need constructive criticism to get better. Is Nasus still farming minions at 10 minutes when he should be grouping? Tell him he is an idiot. He will thank you later. Also, use that question mark ping on top of whoever is being an idiot and do so as often as possible. He will concentrate better if he knows his team is paying attention to him.

7. Black cleaver shreds armor, so all physical damage dealers do more damage to the target. This is why it is often a good idea to have full ad team comps -- you can make better use of that armor shred.

I'll post more advice once I get promoted to Bronze 4.