Counter-jungling is the least about trying to steal the opponent's camps. Its mostly about screwing up the opposing team's jungler so hard that his early game leading into mid-game is unrecoverable.
Even if you were able to steal both camps, good junglers would just take red and gank earlier.
How do you make someone's early game unrecoverable?
Well there are different ways.
1) Kill him.
2) Steal his BUFFS.
In order to kill him, you need to know the workings of the enemy jungler. You need to know his route, the approximate time he would take per camp and what point in time he would be the weakest.
For example, a jungle Olaf would be the weakest right after red. So if you gank him at that point, not only do you get first blood, you also get both buffs.
If you know the opponent is a high HP jungler (like Warwick) or you suspect hes stronger than you, then you should focus on stealing instead. So try Smiting his red or blue when hes about to kill it/Smite it.
If nothing, you would at least
a) scare the **** out of him
b) know exactly where he is
c) delay his ganking.