First of all, how much did you smoke?
Whenever I smoke, I inhale until it starts to burn, take a couple more light puffs, and then inhale air away from the joint/bong until my lungs are full. Some people like to hold it in for a second or to, I'm not sure if it makes a difference. Diffusion (wait...is it diffusion or osmosis?) through the alveoli is pretty quick.
I will usually be stoned within five to seven minutes (actually stoned, not just "feeling it") if I inhale this way. Less, if I'm using a bong.
In my opinion, it is KEY - absolutely imperative - that you inhale more air after taking a hit. It keeps the THC in your lungs (or moves it there if its still in your mouth or windpipe), and you're less likely to cough than if you just take the hit and hold.
And maybe you're just not taking enough hits. You're very, very unlikely to get stoned off one or two hits unless you're smoking some CRAZY shit.