The best method for separating water from a mixture depends on the state of the substance(s) mixed with water.
Water can be separated from insoluble solids by filtration. Anything dissolved in water will pass through the filter paper with the water, so another method of separation would need to be employed.
If a solid solute is dissolved in water, the water can be separated by evaporation or distillation, in which water is boiled off, collected as vapor and condensed to liquid.
Water is separated from other pure liquids by fractional distillation. For this procedure the mixture is boiled and each "fraction" or separate substance is collected at its boiling point. The boiling point will remain relatively constant until the substance with the lowest boiling point has boiled off, then increases to the temperature at which the next fraction begins to boil.