If you run out of currency, you can purchase more gems in the bank.
Moreover, you can earn more coins and gems by voting, watching rewarded videos, keeping the challenge streak active, and regularly collecting your daily prize in the bank and even more rewards in the Season Pass. Besides, we can recommend entering "Dresscode-free" challenges as they have no Glamour Point requirements and Dress Code, so you can style any look you wish using only owned/worn items and still have a chance to score 5 stars.
Besides, you can also complete special Tapjoy offers to receive gems for free (available on Android devices only).