I agree with the existing comments. I have increased my life insurance policy several times (first when married, then bought house, then kid, kid, kid, etc). If you reevlaute life insurance, I would bump it up to what you might need in the future, not just what's needed today. So, get the $2M policy, not the $1M, for example (you can always drop it later). DIsaibility is also critical and the most overlooked.
529s are great of course, and obvious. But what I like about them best is that every time money comes for holidays/birthdays, I pocket the cash and just electronically drop it into the 529s - quick and easy and it actually does add up. That said, I have decided we are not going to stretch/reach/struggle to fully fund 529s any time soon (unless income is really good / win the lotto / etc). It's pretty tough to fully fund the plans and it's imposible to know what life will be like 20 years from now, so we've taken the approach of funding what we can, but it's a second tier priority.
The other biggest change is simply how much kids cost, which seems partly obvious. We have 4 kids. It's absolutely stunning if I add up what we spend ourselves vs what we spend on the kids. Now this is not a big deal if income is ok, but I imagine it can be if income is tight. The reason being kids don't (generally) cost you a percentage of your income, they cost a fixed amount. So if you make $150k or $50k kids will generally cost about the same and impact each family differently. This is not an accurate budget, but I'm thinking of things we've spent money on in the last 3 months.... swim lessons ($500), piano lessons ($750), hockey team ($500), school supplies ($250), birthday party ($250), santa ($1000), shoes & clothes ($400), allowances ($100), new bike ($100), etc. We spend $1000/mo on food and other household items due to kids. Then lifestyle changes like larger vehicles, more expensive family vacations, etc. And of course there's college, weddings, etc. Everything can be done cheaper and no family needs to do it all, but life gets pricey every day ($80 yesterday for a cheap buffet after church). I don't track the annual cost, but if we really weigh everything all in, I'll bet it costs us $50k / year vs. what it would cost us to live without kids... and that probably still leaves college totally unfunded.