Identify the elements present in the compound
Write the chemical formula of the compound
Determine the charge or combining capacity of each element or ion
Use common valency rules for known elements and groups
For ionic compounds, balance the total positive and negative charges
For covalent compounds, count the number of bonds formed by each atom
Use the criss-cross method if needed to infer valency from the formula
Check polyatomic ions as single units when present
Verify that the sum of valencies gives a neutral compound
Confirm the valency by comparing with standard valency tables