For the outside hose faucets or hose bib, you can purchase an styrofoam cover that covers the valve and fits snuggly up against the house. The cover is insulated and keeps the wind away from the valve and water supply line.

It attches to the valve using a plastic zip cord that slips over the valve handle, then pulling the zip cord will press the cover up against the house.

The Presure Vacumn Breaker or PFB valve is located on the irregation system supply line, ussually located on the side of the house near the irrigation zone valve box. 

This valve is required by city code to prevent backflow of water into the house water supply line.

On the top is a plastic cover, this should be checked often during cold weather. If the cap is cracked, it's a sign that, at one point the valve had froze. If there is a severe enough freeze in the line the cap will break and the valve will release water. If this happens, it is very costly to replace, it ussually requires a plumber.

For the PVB valve on the irrigation water line, you can install an insulating blanket over the entire valve body and water lines. 

The blanket is fairly inexpensive and works very good keeping the cold and wind off the valve during freeze conditions.

The blankets slips over the valve and pipes and secures at the base to the ground or pipes.

For pool owners, Cold and wind can cause your pool filter equipment to freeze, which can be expensive to repair or replace. 

You can use a patio chair cover to slide over the pool pump, filter and water lines. I know it sounds strange, but the canvas material is excellent at blocking wind.

I have found that this works great, it fits over all the filter equipment and allows you to run the filter without having to remove it.