Give each substituent a number to indicate the carbon atom to which the substituent is bonded - use a hyphen to connect the number to the name
If there's one substituent, number the parent chain from the end that gives the substituent the lower number
If there are two or more identical substituents, number the parent chain from the end that gives the lower number to the substituent encountered first
If there are two or more different substituents, list them in alphabetical order and number the chain from the end that gives the lower number to the substituent encountered first
Alphabetize the name of the constituents and then add the prefixes di, tri, etc
When there are two or more parent chains of equal length, choose the parent chain with the greater number of constituents