Examine the mixture in a clear container such as a beaker or test tube. Try to determine whether or not there are differentiated layers, or substances of different sizes or physical makeup. For example, look for floating solids or other insoluble items.
Try to make the mixture homogeneous by vigorously stirring, shaking, heating or otherwise agitating the mixture. Never heat or agitate a mixture if you believe it has the capacity for a dangerous chemical reaction. If the different parts of the mixture combine and stay thoroughly mixed and indistinguishable, you have created a homogeneous solution.
Determine if the different parts of the mixture have different physical properties. While some solutions and mixtures may appear to mix thoroughly, they can be separated by advanced equipment. A homogeneous mixture takes separate elements and combines them so that they have the same physical properties. For example, blood is heterogeneous, although it appears to be completely mixed and homogeneous. In a centrifuge or when it dries, blood separates to reveal different parts such as plasma and blood cells.
Separate the different elements of the mixture by titration, pouring them into different containers or simply removing solids. If you can separate the mixture into parts, you have a heterogeneous mixture.