Clash Royale is more than just placing cards down, and hoping for the best. Its about positive elixir trades, defence, and synergy.
Kiting is a necessary skill in clash royale. It consists of using a tower-focused troop placed at the bridge at a position where itll lure a slow high elixir card across the map. With this lure, it engages the card with both towers, mowing down the HP of cards like P.E.K.K.A ( as pictured above ) it often results in a positive elixir trade. This can also be done with buildings. ( in the middle of your half ) in order to defend both sides, and maximise card efficiency.
Positive elixir trades are when a card with a lower elixir cost defends an opposing card with a higher elixir cost. This is absolutely required as a skill in clash royale, as with out it, a player is bound to lose, as with negative elixir trades ( opposite ) you'll be at an elixir disadvantage. Resulting in a inevitable loss. for example, Bandit (3 elixir) countering mega knight (7 elixir) With that you gain a 4 elixir advantage.
Sniping is composed of utilising a cards range. for example, this firecracker chart. ( above ). We can utilise firecracker on the right side to target the left and the right. Basically bringing max value out of the card. We can also use pierce in this aspect. With the magic archers pierce, we can put it at the bridge, so that when a card is placed infront of it, the magic archers attacks can damage the tower.