A simple tarpaulin can be used to make a temporary privacy fence out of an existing wooden fence. Tarpaulins used to only come in shiny blue, but are now available in a wide array of colors. They're durable, and can be draped over the fence and stapled to the fence posts and cross members. The tarpaulin can be easily removed once your need for privacy for your garden party or home renovation is completed. The downside to using a tarpaulin is it's very temporary, as they will tear as they degrade. They may also be noisy if your fence is located in a high-wind environment.
Many commercial products are made specifically for converting chain-link fences into privacy fences. These products are long, thin pieces of vinyl woven between the chain links. They can be just as readily used on a wooden fence, woven between the vertical pieces and stapled or zip-tied to the fence posts to prevent them from moving in the wind. Vinyl slats are designed for long-term installation, so they can be left up permanently with little maintenance, should the need arise. They can also typically be painted to match your fence color, using exterior vinyl paint.
Corrugated plastic material is often used for porch roofs and pergola coverings. They're typically constructed of PVC and fiberglass, and can be easily set against a wooden fence and screwed into place. More rigid than tarpaulins, they can extend some distance above the wooden fence before they'll be bent by the wind. Additionally, they can be painted and repainted, and can be left installed for as long as needed.
A number of fabric fencing materials are commercially available and are designed for creating a privacy screen. You may have seen them employed on fences surrounding baseball and softball fields. It's designed for permanent installation, and requires little maintenance, but is a more expensive option than the aforementioned choices. The fabric comes in a variety of colors and levels of transparency, ranging from relatively transparent to completely opaque.