Cottony Camellia Scale
If you have Cottony Camellia/taxus scale, you want to treat them when the eggs have just hatched and they are in the vulnerable "crawler" stage, which could be now--although it might be a little early-- or in the next couple of weeks. Look for the small insects on the undersides of the leaves, and watch for movement. Spray them with a light summer/horticultural oil, or an insecticidal soap, being sure to reach all sides of the leaves and branches.
You also want to make sure the taxus is otherwise healthy-- a healthy plant will withstand the stress of an insect infestation better than a weakened one.