If polyatomic ions appear on both sides, balance them as one group
Leave elements that are not bonded for last
If you have a combustion reaction (CxHy + O2 --> CO2 + H2O) and the coefficient in front of H2O is odd, you need to start over with a 2 in front of the hydrocarbon (CxHy).
NO FRACTIONS!!!
DO NOT CHANGE SUBSCRIPTS!!!!!!! (Notice how it is bold and italicized)
Reduce if possible, do not leave coefficients of 2, 2, and 4.