Turned In
We see Blondie turn Tuco in for a $2,000 reward for a bounty out on him. Ironically, he shoots him free from the noose moments later. We come to find out that they are teamed up to earn money from the reward on his head.
Follow Through
Angel Eyes is paid $500 to kill a man, which he does. But before he takes the man's life, the man attempts to pay him $1,000 not to kill him and to instead kill the man that sent him. Angel Eyes still kills the man, but when he returns to the man that employed him he ironically kills him as well as he has a code that he sticks to that he must always follow through with the job he is paid to do.
Tuco's Boot
Blondie is walking through the desert alongside Tuco who won't give him water, food nor shade. He wants him to die. We see Blondie lying on the ground and Tuco's boot is next to his head. He goes to fight him by grabbing the boot, but ironically only gets the boot, not the man as Tuco took of his shoe to mess with him and in order to wash his feet in water right in front of Blondie.
Crossing
When soldiers arrive in the desert, Tuco inspects the wagon to find dead men. He crosses himself as he holds one of the men in his arms. But in the very next moment he steals the man's watch and searches through his wallet. This shows Tuco's character.