i am working a Salvia that has extremely brittle branching. I assume last years growth but thin. Maybe 1/8" thick. If you look at them wrong they snap. Would it be better to use guy wires for placement? Am really hesitant to try traditional wiring
Neither is going to work on a species with stiff brittle branching. The bends produced by guy wires are mostly unconvincing and silly looking on such a rugged trunk. Guy wires are more to hold existing developed branches in place.
As said, clip and grow--hard pruning back to the first set of leaves is likely to produce a flush of new growth at the cut site or nearer the trunk. That new growth/shoots can be selected for direction to begin a new "bend" in the branch. New shoot will typically grow in a slightly, or dramatically, different direction than the branch that is producing it.
The process is repeated with new buds at the ends of those previous one that have been cut back hard. This is standard process for most deciduous species and shrubs including boxwood and others with extremely hard wood that won't bend. Branching on the majority of deciduous trees is "built" rather than wired. Wiring hardwood can needlessly break branches, strip bark and new buds if done incorrectly on older wood. New shoots and tertiary branching is typically the only part of D branches that get wire.
Pines and conifers are wired, since even old wood on those species is "bendy." Their wood, even older sections, can stand up to the forces involved that are needed to produce sharp angular turns...