If you have a backyard that is overlooked by neighbors or neighboring windows, here are a few ways to add privacy to your backyard.
Landscaping
Trees and large shrubs add privacy to a backyard, but you may have to be a bit patient.
You can spend a lot of money on large trees and shrubs or you can spend a little money and wait for them to grow (adding fertilizer and watering them regularly should speed up the process).
If you are using trees and shrubs for privacy in your backyard, make sure to get evergreens that do not lose their leaves in the winter.
Another option is to use lattice covered with an evergreen vine.
For movable screening, consider planting tall shrubs in a huge planter on wheels that can be wheeled out of the way when required.
Fencing
You can add a fence to your backyard for added privacy.
The fence can be made of wood, bamboo, metal, or whatever material you desire.
Make sure to check with your neighborhood Home Owner's Association and city to ensure the fencing you desire is allowed.
Patio, Arbor, Covered Porch, or Pergola
Adding an arbor, patio, covered porch, or pergola will add privacy to your backyard.
You can even grow an evergreen vine on your pergola or arbor for even more privacy.
Fabric
If you need privacy on your back porch, consider adding fabric curtains.
You can also add a fabric sail canopy if you require privacy from above.
Berm
A berm is a small hill that can be used for privacy. If you decide to build a berm, ensure that the rainwater does not run into your neighbor's yard and that it will not pool in yours.
Sound Privacy
If you are concerned about sound privacy, either you don't want to hear your neighbors or you don't want them to hear you, consider installing a water feature.
Falling water creates white noise that muffles sound.
You can decide the amount of falling water you need depending on how much sound privacy is needed.