The W4 tells your employer what to withhold for Federal Taxes. If you want more taxes withheld you can eliminate step 3. Adding your dependents allow for the child tax credits to be taken into account when filing your tax return. So eliminating this step will still allow the dependent on your tax return but more money will be withheld from your paycheck. You can also in Step 4 of W4 line c, you can add a dollar amount. This amount will be taken on top of withholdings. Look over this link for more helpful hints: Form W-4 and take home pay.