Prune azaleas after the spring flowers have faded and before the end of June. This will provide enough time for new growth to mature and harden off for winter and for flower buds to form. Avoid cutting back your azaleas too severely. Often after severe cutback, all the energy of a plant goes into foliage production, which may inhibit flowering. If pruning was not the problem, you could have a nutrient imbalance.
Plants overfertilized with nitrogen tend to produce a flush of green growth and fewer flowers.
You may want to take a soil test to determine the pH and other nutrient levels. There are several possible causes for the leaf browning. Follow the stem down toward the base of the plant and see if you have any cracked or split stems. If this is the case, you may have some winter injury. Then the only thing you can do is to cut out the damaged stems close to the ground, making your cut just below where there is healthy stem tissue.