This Salvia Leucantha (Mexican Bush Sage) has some straggly growth that be thinned out. Removed the older branches down to the ground level. (Click on photos to get a closer look.)
These younger branches full of leaves will provide a bountiful display of blooms this fall.
This is Salvia greggii 'Raspberry'. Your "greggiis" may be really big and full of blooms as well as full of these spent blossom stems. They also may be really woody looking with no leaves closer to the ground. Now is the time of year to really cut them back.
Basically, the best (and easist) way it to just take your hedge shears and lop them off straight across the top. If yours are taller and woodier, take them back 1/3 or even 1/2.
This is one of the Bat-faced Cuphea I trimmed in May. Many more branches and all about to bloom.