What are some other ways to minimize tax? The idea of Donor-Advised Funds sounded conceptually interesting, but it appears we would not receive any tax benefits as neither of us itemize.
You say this like you have a religious objection to itemizing. The advice you get will be limited because you have pre-supposed that you *won't* itemize, because you apparently *haven't*. Regarding this specifically, the idea would be to donate enough to the donor-advised fun to make it worthwhile to itemize. The standard deduction is $24,400, so that would be the starting point to consider. (don't forget to take into account your other itemizable things, like your mortgage interest, and local taxes up to the SALT limit)
More generally, don't look at this as an annual exercise; look for things you can double-up on: pay last year and this year, or this year and next year together. Could you do that with your property tax, and still stay under the SALT limits? Look to do that with your charitable contributions, as well. You will take a hit on the odd years (really, you still get to take a standard deduction) but you could make enough progress to itemize sometimes.
We have no kids yet, but the idea of a 529 seemed worth further review although I have very minimal knowledge on them?
A 529 won't help this year: while you may get a tax deduction or credit on your state's plan, it won't do anything for Federal taxes. You could designate yourself as a beneficiary until you have a child, but beware that if things don't work out, you will face taxes plus a 10% penalty for withdrawals, unless you want to do a favor for a relative. (by making them the beneficiary)