Using magnetic attraction- if one of the solid components in the mixture is magnetic, it can easily be separated from a non-magnetic solid using a magnet.
Sieving- in a mixture of bigger and smaller particles we can use a sieve of the right pore size to separate the components.
Using suitable solvents- solids usually have different solubilities in different solvents. By using suitable solvents we can separate solid of different solubilities.