Quote Originally Posted by BobBong
Neem Oil should be applied every 2 or 3 days. Only apply once a day and when applying apply to the underside of the leaves and mist like crazy to ensure you get all the nooks and veins on the underside of the leaf ( as this is where most pests live, underneath the leaf )

hope this helps.
Bob.
Stinky's method will work as well.. may not be as vigorous but it is still applying the neem.
Depending on what stage the plants are in, how bad the infestation is and how badly you want them out of there, you can vary the application method.. I've even hear of people bathing their clones in a light neem solution when bought to ensure that there is nothing there. literally taking the plant washing it in a solution.

Either way, never go above the recommended dosage as this won't necessarily be any more effective and could actually suffocate your plants like Stinky mentioned.