First off, you would have to decide how much you want to invest as future savings. Once you have decided upon that particular amount, you could then go ahead and follow the next few steps.
You should next target all the expenses especially the ones with your credit cards. If your kids in their teens are given access to such credit cards, it would be prudent to get them back.
Next have a meeting with your family and come up with a list of expenditure incurred on a monthly basis. Then go ahead and check the expenses that could be eliminated. Eliminate such expenses with the concurrence of your entire family. Set an example and strike out a few expenses that you can live without so that the others can follow suit.
Once such expenses are eliminated, see how much money you would have on hand. Calculate the monthly credit card debt that needs to be paid back and see how much money is left. Now make certain that you use this money towards your kids’ college fund or in some kind of recurring deposit scheme that would give you better financial gains.