To favour remineralisation over demineralisation, you really need to attack both sides of that equilibrium. Obviously, the most important factor to enhance remineralisation is fluoride. It speeds up the process dramatically. That is because of the high level of cation-seeking potential for the element. It is the most electro-negative of all elements and therefore is searching for calcium or cations and it favours the formation or the precipitation of appetite crystals and favours remineralisation.
At the same time, you need to also decrease the amount of demineralisation; that is the attack that occurs every time we eat a meal, have a snack, drink a coffee with sugar in it or a Coke or whatever. So the best way to do that is (1) reduce the frequency with which we have those attacks, the number of times we snack in a day, and (2) the second factor is improve oral hygiene. The better the oral hygiene the less the amount of damage. There is much more acid produced in an older plaque by a logarhythmic factor as compared to a plaque that is say 12 hours or less of age. So brushing, for example, twice a day, flossing and so on, greatly enhances the potential for remineralisation by decreasing the amount of de-mineralisation.