How Does Do Jungle?

So I've been making strides in my play, trying to play only a limited number of champs that I have been pulling good results with. This has led me so far to playing a really good Darius Top and Leona Support. I'm still working on getting a Main for mid lane and adc positions. But I am getting closer to those roles than I am pulling for the Jungle position.

My main problem? Ganks. I am horrible horrible horrible at ganking. I can clear the jungle camps like no tomorrow. I can even solo Dragon with most champs (except Hecarim for some reason) by Level 4. The Jungle doesn't scare me.

But holy crap do I suck at actually ganking lanes. My map awareness has got to be the problem. Because everytime I go to visit a lane, there's no gank potential because the enemy is already pushed to their turret and are turret hugging so I can't risk ganking unless I die. If they are not hugging turret, my team mate is not in lane because they had to go back or died or something a long those lines.

How do you do it? How do you know when to capitalize and catch the enemy off guard enough so that you can gank successfully? Most of the time it seems like my attempts just result in me popping in, unleashing ult or some form of tackle ability, start getting focused down hella hard and have to retreat before I die. And it only gets worse the more I try to gank because I'm not getting any XP from my failed ganks, and the failed ganks are taking time away from when I could be Jungle farming. So I end up just AFK in the Jungle for days because I'm too afraid to make the jump and gank a lane and risk falling further and further behind.

How does do Jungle?