You need to buy Spellbook ($10) in order to gain more DEC (Dark Energy Crystals) every time you win the battle. With DEC you can buy/ rent a card and summoners, you can also buy/ sell DEC via Pancakeswap in BSC network.
Pay more attention of your ECR (Energy Capture Rate). Always maintain between 85-100% rate, because your DEC winning in the battle affected by this ECR rate. For example, your rate is 90% than you will get around 0.9 DEC. This role means playing Splinterlands has to be more fun and relax. And if you do not want to wait any longer (it needs 1%/hour to recovery) you can create another account just to exercise yourself.
You can also rent card/ summoners at Peakmonsters.com, and I suggest to rent first before decided to buy it because you can always cancel your order if you do not like or choose the wrong card.
Sometimes it is frustrated when we got a low MANA cap. You can try this tips but not 100% guarantee that you can win the battle. Pick one Splinter with high Live and high attack, and pick the rest with ability to attack from behind.
Always complete the Daily task to gain daily reward because it is randomly content the rare cards. Look at the instruction like “5 wins w/snipe” means you have to win 5 battle with one of the snipe monster card. We can sell/ rent this reward card. If you got a gold card with Level 3, it is better to rent it.
Have a weaken/ magical card on your battle is never get wrong as long as your MANA cap is more than 20.
Have a heal card with high Live as your front card in the battle when you got lower MANA cap.
Rent a Furious chicken card, it helps you to counterattack with 0 MANA cap needed.
I'm more than happy to receive any tips on the comment section down below, please also give your upvote. Thanks so much!