At one time, wallpaper paste was made from flour and water. Today there are ready-made mixes and powders on the market. If you choose a powder, it is important to mix it correctly so it is effective in holding the paper to the wall.
Read the manufacturer's directions to find out the amount of water needed for the wallpaper powder you purchased.
Pour cold water into a clean bucket. Remember, less is better; you can always add more water if the paste is too thick.
Pull a piece of string taut over the top of the bucket and tie each end to the handle of the bucket. When mixing the paste, you can use the string to wipe off excess paste from your mixing stick.
Add the wallpaper powder to the water while stirring with a clean mixing stick. Add the powder slowly. Too much powder at once will make the paste too lumpy and you won't be able to use it.
Stir the powder and water until the paste is thick.
Leave the paste to sit for about 10 to 20 minutes and then stir again. Check the directions of your specific wallpaper powder for the recommended times.