Garden To Do in Winter

Pruning

Hydrangea Paniculata - (Late December ~ Early January)  Flowers on the new growth, so remove the last year's growth. 
Cut the branches, leaving 4-5 buds.  To control the size, prune leaving 1 bud.
Cut off downward growing branches
Cut off weak, skinny branches
Remove crossing branches.

Trees
Remove waterspouts
Remove crossing branches
Remove branches growing toward the inside of the tree.
If desired, heading cut branches to promote growth.