Jungling: Unopposed

Sometimes you may face a team without a jungler, leaving your top lane in a precarious 1v2 situation. With a jungler your team has an inherent advantage, but only so long as you take advantage of your position.

First and foremost you need to make sure your top lane is secure. While some champions can fare decently in a 1v2 situation, the vast majority can not. It's important to communicate with your top lane, gauge their confidence, and help them out preferentially (i.e. camp their lane). Winning a 1v2 top lane almost guarantees you'll win the game.

Next, take full advantage of the lack of a jungler on the enemy team. It should be impossible for them to get any of their buffs, dragon, or Baron. If your top lane is safe you can get obscene amounts of farm on the right jungler, enough to match solo lanes. So long as you don't neglect top lane your team's lead entering into the mid game is assured.

Finally, watch for desperate moves from the enemy team. Backed into a corner, the top lane duo is likely to roam and try to make plays in other lanes. This is particularly dangerous because your other teammates have likely been playing very aggressively without an enemy jungler to worry about. Stopping these last throes of enemy resistance will seal your victory, while ignoring them will drag out the game and potentially lead to defeat.

With enough experience it becomes relatively easy to punish the enemy team for failing to pick a jungler. Your team has inherent advantages, it's just a matter of learning to apply and extend them.