New W4 0 and 1

I’ve been at my job for 9 years and have had my withholding set to 0. I recently got married and had a child. I now file Married Jointly but get a large tax refund. I’m trying to reduce my withholding to get more on my check and less of a refund. Ideally $0. 

my employer gave me the new W4 to fill out and the thing makes no sense to me. The online calculator is useless because my paychecks vary by up to $1,000 a check and I get a large bonus every year. So the calculator just doesn’t work. 

I have no idea what to put on this thing to achieve my goal.