Overall, financial strategies for blended families should not be that much different from strategies for a traditional family. Hopefully couples have already talked about such things as their current finances and their financial goals for the future. In addition, they should have already created a budget to ensure their daily living expenses are covered after their marriage, with an eye toward saving money for future expenses such as a home or a large purchase such as another vehicle. Both adult parties of the blended family, in order to get off on the right foot, also need to understand there could be monthly expenses from prior relationships or marriages such as alimony or child support. The best way to minimize issues with these types of monthly obligations is with simple acceptance. Couples are better served by presenting a united front and tackling what might be a tight budget, together, rather than going into separate emotional corners and considering thoughts like, "it's his alimony payment, not mine" or "her ex should support her child, not me".
Responsible couples, whether they have a blended family or not, will be best served by following the sage advice of "don't sweat the small stuff". Focus on unifying around the big-ticket items like housing, child care, transportation, alimony and child support. Allow each other to have a certain amount of money for which one does not have to answer to the other -- and be prepared that it might be a small amount to begin with.
Couples who learn to embrace the unique financial challenges presented by a blended family and who brainstorm together to solve those challenges will find their relationship strengthening and deepening over time.