This is gonna sound horrible coming from a Shaco main, but I almost never invade early game. I take the enemy's jungle if I know they're somewhere else, but as far as actual counter-jungling goes, I don't do it. Reason being, I always think: "why would I set one person behind when I can spam ganks and set 3/4 of them behind?" If I leave the lanes to their own devices, some of them may win on their own. But let's be honest: why leave it to chance? If you can get all three lanes rolling by ganking, there's a better chance of them not only winning on their own but being safer from opposing ganks. No jungler wants to gank a lane that's already behind. And with Shaco's early game power, he can get opposing laners behind faster than anyone else. Against certain junglers I make exceptions of course, mostly those who need to farm a Devourer, or who need to rush level 6: Master Yi, Fiddle, Amumu, Shyvanna, Kindred, Warwick, and Kayle are all junglers I occasionally invade. With anyone else, I focus on the lanes, steal camps when I can, and secure dragons/herald to keep the laners fed and happy.
This tactic also helps dissuade the laners from complaining. If the laners are constantly getting ganks, they are less likely to have negative attitudes, which makes for a better playing environment. Laners will be more willing to listen to shotcalls, group as a team, accept advice, and contribute to warding if they feel like they are getting help throughout lane phase. By contrast, junglers who don't make their presence known in the lanes (e.g. those who simply powerfarm, or counter-jungle all the time) risk angering their team mates. Why would you put your own team on tilt if you can help it? It's just a recipe for disaster. Naturally the best solution is to help the lanes as much as possible, which is extremely easy to do with Shaco. Counter-jungling is a good high elo strategy, since the laners are less likely to require constant help, but in the lower ranks it's less important.