Don't cut anything now.....
In the spring cut all the dead stuff off the pampas grass, do it early before any green shows.
If your spring bloomers, lilac and wigelia need pruning for shape, do it in the spring AFTER blooming....if they are not getting too big, do nothing.
In very early spring, cut the top growth on the clematis back by half...but you don't say what kind of clematis it is....I assume spring flowering.
Linda C

Good advice there Illinois. I would just add that as a general rule prune immediately after flowering those shrubs that flower on the previous years growth. That gives them time to build up and ripen new wood which will flower the next year.
Prune in autumn or spring (spring in very cold climates) those shrub that flower on current years growths.

Observe your shrubs and you will soon learn their habits of growth.

As already mentioned the pruning of Clematis is dependent upon the type. Just a little about Clematis on my website - link below.

Peter

Here is a link that might be useful: Clematis

AAH....but Peter....how to know just what sort of clematis you have....when you buy them for a song at a season end sale!
I have adopted the wait and see mode for the 3 new strangers I bought in July.
Linda C