After a hard freeze, you may be tempted to rush out and prune off seemingly dead plant parts. However, this may ultimately do more harm than good. Even in cold climates, plants will sometimes try to resprout on warm days, only to be hit hard again with a subsequent frost.
Wait until weather has warmed up significantly and the chances of another frost are pretty much over before pruning. Some plants take a very long time to recover from a hard freeze; sometimes 6 to 9 months! It pays to be patient before pruning or giving up on a plant altogether.
When temperatures do warm up and the plant begins to start new growth, now you can ascertain what is dead and what is not. Always prune branches back to the point of beginning, but keep cuts from harming the bark or main stem.
Of course, the best way to avoid dealing with plants freezing is selecting species hardy to your area where this is not a problem. Contact your local Extension Service office for a list of cold-hardy plants.