Most of the time uphill technical becomes even more difficult when the rider tries to steer a line through the mess. This is usually a bad decision.
It is very often better to not steer but instead go straight over obstacles. Steering can compromise your balance.
Like the others have said, use your body weight fore and aft to drive the momentum up and over.
Another mistake is gearing selection that is too short. If you go for the granny everytime you approach a difficult section, then you might be losing too much momentum. Momentum is your friend in all things mountain biking related. It's just knowing how much is either too little or too much. That is just a matter of practice.
So...
Balance: Go over, not around.
Momentum: Go faster, not slower.