There are many way to do this but it depends a lot on which Schiff base you are trying to make.
Some Schiff bases are formed very easily when aldehyde and amine are added just with mixing. Others need refluxing and a catalyst such as a mineral acid.
The metal complexes can also be formed in different ways. In some cases the Schiff base is formed first and then the metal salt is added in a suitable solvent. In other cases, the metal salt can be added as part of the Schiff base reaction so that both occurs in the one step.
I have attached just one example of Schiff base formation and it's metal complex.
Is there a specific Schiff base metal complex you are trying to make?
Conference Paper SYNTHESIS AND CHARACTERIZATION OF SCHIFF BASE MN (II) METAL ...