The best way to earn coins is to be victorious in Tour matches, as this is the main source of income in Tennis Clash.
However, this is not the only to way to earn coins! You can also watch ads to build your savings. Simply tap the "Free Coins" button on the Home screen when it's available. To know more about the Free Coins ads, please click here!
Keep in mind that if you were unfortunate to go on a losing streak and run out of coins, you can always purchase coin packs in the store tab.