First, do no harm.
I can’t tell you how many times I have heard: “It didn’t bloom.” Or worse: “It never blooms” and the problem turns out to be that somebody is pruning the shrubs at the wrong time of year, cutting off all of the flower buds
So what can you do in the garden?
Some shrubs are grown for foliage more than for flowers, and are usually pruned in early spring. The shrubs on this list can be pruned this month. Just do it from frozen ground, or ground that has already dried out, or from a path. In general, you can remove up to one third of the plant. I like to do this with very sharp clippers and bypass pruners.
If you are doing a lot of them, it is nice to have separate clippers for dead and green wood, because dead wood tends to dull clippers. Extra sharp blades for clean cuts on green wood is worth it.. A quick spray of bleach or alcohol between plants will help halt the spread of disease.
Alpine Currant: If you really want to keep it, remove dead wood, shape it, don’t worry about it. It is too stingy to kill by accident.
Red-Twigged Dogwood: Grown for the red stems, which only occur on immature wood. Cut out old, no-longer-red wood every spring, trim aggressively (if you must) to control size. New growth will be a nice bright red for next winter.
Purpleleaf Sandcherry: The great purple beasts. These are very susceptible to pests and disease. Prune to increase sunlight and open up air circulation.
Barberry: Increasing invasive in the Midwest. Maybe it is time to stop using this one.
Smokebush: This can be cut back to the ground every year to great effect.
Ninebark: Prune to shape, but it does bloom on last year’s wood.
Staghorn Sumac: Staghorn can be cut to the ground, or just remove deadwood and try to control spread as desired.
Burning Bush: Fun to prune, because you can do anything to them, anything at all, but increasingly invasive. Do not use where they can escape to natural areas.