Standard rule of thumb I have used in the past still holds true ... the lower wage earner fills in the W-4 choosing the SINGLE filing status and NOT entering any kids at all. Then the higher wage earner chooses Married Joint and can either claim the kids or not depending on what you need to be withheld. To have the max withheld both spouses claim SINGLE with or without the kids on the higher wage earner... this will force a higher refund.
Use the Tax Withholding Estimator on the IRS web site to figure out what you and your spouse should each put on the W-4 forms that you give to your employers. It's much easier than using the worksheets on the form. It will let you adjust your withholding to get the approximate refund amount that you want.
Tax Withholding Estimator
