@Cindy Yaa For managing properties overseas, I'd definitely hire a local property manager for where ever the properties are. I recommend this mainly because if something happens when y'all are in different time zones the managers can respond a lot faster and have a lot more local connections with contractors. Plus this will reduce a lot of the headache you may have if y'all are managing them yourselves. Plus local property managers will also be up to date about the local laws. Assuming y'all have already done this..?
Outside of that other business strategies for protecting your assets would be talking to more professionals for legal, estate planning & accounting advice for being overseas. Should do this with your local ones closer to with y'all live as well as maybe closer to your properties or a company that specializes with overseas clients that invest.
In general for the U.S. you'd want to consider legal entities for both liability protection and helping you save more money. This will also help you run them as businesses. Overall I'd highly recommending setting up as many systems as possible that makes everything flow, automated, efficient and effective to where y'all don't have to deal with a lot.
What all else are y'all considering?