In the words of Stonewall:
If you think your champion has great jungle clear or ganks or damage (Zyra, Jayce, whatever), how do you address the clear or sustain or ganks of someone like Mundo or Amumu or Xin Zhao? (paraphrased)
"Is his ganking super-mega-kawai-sugoi level? Is his sustain ultra-mega-giga level? Is his damage super-ultra-giga-kawai-senpai-pancake-taco level?"
https://www.youtube.com/watch?v=fZRSPDUKxYI
If you think you're "great," then what would you call ZionSpartan or Keane? How about Faker?
Passive Aggressive Rant Over. Real advice to follow:
If you can't defend against a gank, you're not using your map awareness well enough. When you have wards out, do not go past a distance you can cover in the time between you seeing the enemy jungler and him/her kicking your ass into oblivion.
Learn to freeze lanes and manipulate minion waves--go aggressive when you see the enemy jungler elsewhere, and let the waves push back to you so you can farm closer to tower.
Probably the biggest thing, though, is to be careful about overextending without backup. When you see your enemy laner start to pull back from you and let you push, that's when you freeze the lane. Letting the enemy push is the clearest example of baiting a gank, and it fools just about everyone.
I realize I'm a filthy Bronzie, so you don't have to listen to me if you don't want to. This is, however, the same advice I give to my friends who've climbed from Bronze 5 to Silver 1, and many of whom are still climbing.