depends on how much you want to spend.

under 50$: buy monthly cards + naruto froggy 100 ingots option. recharge when there's platinum recharge.

over 50$ but under 150$: the same as before, but add also naruto froggy 5k option. recharge when there's platinum recharge for the 1st and 2nd tier and recharge for the other part during shinobi feast (2nd best low cashing option).

over 150$ but under 600$: add in jonin medal and recharge esclusively when there are 2-3 rebates together.

over 600$: do what you want.