There are so many factors that determine why you may have owed this year. The best way to make sure you have the correct amount withheld and possibly not owe next year is to use the Turbo Tax W4 Calculator.
https://turbotax.intuit.com/tax-tools/calculators/w4/
The calculator will help you complete your W4 correctly and provide the necessary amounts for your employer(s) to withhold. Be sure to gather all paystubs, copy of your previous tax return, and child care expenses, if necessary.