Open your Bags only when you’re sure you can replace its slot with a high-level Bag.
It’s absolutely alright if your bags are ready to open. Don’t just open them yet. If you open the bag immediately, and you’re playing in Tour 1 or Tour 2, then your empty slot will get a Tour 1 or Tour 2 bag. That won’t be a good situation because now you’re stuck with a low level bag for three hours without any slots for high level bags. So don’t open the ready bags and grind your way up the Tours. When you are at a levelled tour, then open then bag and free up the slot, so that when you win a game, you’ll get a high level bag. Your aim in Tennis Clash should be securing high-level bags, because they contain cards and upgrades that will ensure that you’re ahead of the meta. It’s alright if your bags are ready to be opened to 1-2 hours. A high level bag gives much more rewards than a low level bag, helps you make more coins, gems, and upgrade your gear quicker.
Take note of your rank in your League
Make sure you’re in the Top 25 of your league, which will allow you to promote to the next higher league. Each higher league will give you 10% more cards. Ideally, you should be spending two weeks maximum in a particular league. If you spend more than two weeks in a league, then you know that you aren’t growing your player at an optimum pace. So, use the league also to judge how you’re doing. Being Top 25 in a league isn’t that difficult if you follow the tips mentioned about. Just, don’t get demoted to an inferior league, that will seriously hamper your progress.