Balance your deck
A deck should contains card which can attack ground, air, and crowd units and towers.
Stick to one deck
You will have enough cards to level up and reach 300 trophies easy with any types of decks. However, post-3000 is a real challenge. You can’t possibly level up all cards without paying a lot of money. Try to stick to one desk if possible. You must check current meta and stick to the deck you like.
Spend gold carefully
Only spend gold to update used cards. The biggest mistake of beginners are spending gold on leveling up every card. It is economic to buy the first 3 cards of common and rare types in the shop. You will donate them to clan members and get back the money and a little bit of tower experiences. You should only buy Epic cards that is in your deck.
Always test new cards
It is recommended to test a new card in training or friendly battles. Training is not ideal to see how your card works in real situation but it give you basic info of a card and how you will use it in your strategy. If you have some free gems, you can test in Classic Challenge.
Don’t attack first and don’t rush attack
Try waiting enough elixirs to deploy cards based on a strategy! Rush attack will be easily countered when you don’t have enough elixirs to deploy supporting cards. If your starting cards favor attacking, deploy card at the back so they can slowly walk to the front. Hog deck is exceptional, deploy it right a way with a supporting card like Fire/Ice Spirit or Log.
Don’t drop trophies
Many players want to keep their trophies at a certain number because they are afraid of loosing to other players with higher level cards. Higher arenas have higher chance of giving better cards and allow you to request more cards.
Watch TV Royale
It is one of the best sources to see how other players in your arena choosing deck and planning strategy. By watching replays on TV Royale, you will increase experiences and discover new strategy to use for your deck.
Don’t be afraid of loosing
The sooner you realize this, the better you can feel. It is a Clash Royale player’s life. Any player will encounter a winning streak then a loosing streak.
Donating and requesting
Donating gives you money, requesting gives you cards.
If you don’t mind spending a bit money, special offers from shop is the cheapest way to buy cards. With $10, it can help you save many months of obtaining free gems and golds.