As mentioned, save your cp for rebates etc.

Mostly make good use of your ingot on froggy event, good return exchange rate ingot to coupons.

Also join the Shinobi Feast or Konoha Special Sales, like spending 195 ingot for a secret scroll pack to gain 20 lucky points.

It is like a lucky draw with a chance to get free golden essence which are usually hard to get and really expensive.

(It is daily draw so you got 6 chances to win)

Most of the time is all about patience and spend your coupon wisely.

As for power progression, try to maximize your Ninjas Assist and Secret scrolls for more overall team power up.

And also focus equipment refine, charms magatama, runes on P1 ninja then P2 and so forth.

Hope these advices help.