To increase your café's tip percentage, you need to earn style points and fill up the tip bar.

Style Points can be obtained by placing items containing Style Points in a café or by opening stylish gifts. Once you earn enough style points to fill the tip bar, the tip percentage will increase.

The main style of the cafeteria is the style that gives the most style points. Therefore, bank offers will appear in the main style.

In order for a desirable style to become the main style, it must carry more style points.
To do this, you need to buy this style furniture, which brings more style points, and then place it in the cafe.

After that, wait until the offers in the bank are refreshed, and you will see the devices in a new style among the offers, which you can purchase to replace the old ones.