Hi Adam64, It can be tricky finding that sweet spot of no tax due and no refund! There is a W-4 Calculator that takes you step-by-step through the worksheet. The required information can usually be found on your prior year's tax return or your current pay stubs. You'll need to make adjustments for changes from the previous year to make sure it reflects your current situation.
https://turbotax.intuit.com/tax-tools/calculators/w4/
Once you complete the form, give it to your employer. Then, keep a close eye on your next few paychecks to see how the changes impacted your federal income tax withholding.
I hope this is helpful!