@Teriann,
About what you mentioned: "You gave a "trick" : start a story arch, and before reaching the climax, start a second story arch, and then substitute the second climax for the first."
This will probably really feel like a "trick" to the reader (=a stiff method). I don't like that method that much. There is a much better way to come up with an interesting storyline.
This is a blueprint or a spine of a good story:
Act 1
-the hero lives in his ordinary world and has a need (the secondary storyline he is not or partially aware of and is not reacting to)
-something happens and the hero is called into immediate action
-the hero refuses, doesn't want to leave his comfort zone while getting to know his enemy for the first time
-a supernatural aid, friend, thing or mentor kicks the hero into action
Act 2, Part 1, 25%
-the hero enters the world of adventure (the special world, the primary story line)
-the hero makes a plan to defeat the enemy and finds tests, allies and enemies
-the enemy launches a counter attack
-the hero goes to the most dangerous place in the story, usually the enemy's camp
Act 2, Part 2, 50%
-he has a traumatic fight with the enemy which he enters for personal reason and "dies" (is defeated somehow)
-after that he feels the consequences of the fight (he either wins or looses something momentarily)
-he gains knowledge with that and changes his motives to fight (becomes more selfless)
-meanwhile the enemy changes somehow or reveals himself more or differently
Act 3, 75%
-the hero has to go make a decision to go back to his ordinary world and the enemy follows him there
-the hero comes close to death (usually is wounded physically in some way)
-the hero has one final battle, this time in his own world, and this time for a cause larger than himself
-he achieves both the "greater goal" (the primary storyline) and his "private goal" (secondary storyline) at the same time in some way
-the world is changed somehow because of the hero's actions, and the hero himself is changed, too.
Instead of a "story arc substitution trick" this blueprint has "the inner or secondary" and the "outer or primary story line ", tied together by one motive.
Applied to "The Miller's Tale" from The Canterbury Tales, it goes like this:
Act 1:
Nicolas rents a room from the carpenter and lives there, studying astronomy, loitering around. The carpenter marries a young girl and Nicolas wants to lay her ("inner or secondary story line"). She refuses at first, then says okay, but since her husband is jealous, Nicolas is forced into leaving his lazy lifestyle and come up with a plan to get her. Meanwhile we meet Nicolas opponent, another guy interested in nailing the wife. A sleazy singer who hangs around in the local pubs.
Act2:
Nicolas pretends he has read in the stars that a flood comes. He convinces the carpenter to hang up a boat in his house, load it with food and stay there two days until the water comes ("outer or primary story line"). The carpenter does and all three get into the boat that night. Once the carpenter is asleep, Nicolas and the wife get out and do it in the carpenters bed (the most dangerous place of the story for Nicolas). Now the enemy (the singer) comes to the house to get a kiss from the wife. The wife pokes her behind through a hole and he kisses that instead of her face, realizes that and swears revenge. (turns from a drooling admirer to a hater)
Act 3:
The enemy comes back with a hot iron, pretends he has a ring for the wife in exchange for another kiss. This time Nicolas pokes out his behind and gets seriously wounded as the singer hits him with it. Nicolas cries for water to cool his behind, which wakes the carpenter, who is still sleeping in the boat under the roof. He cuts the ropes of the boat and smashes down to the ground, breaking his arm. The town comes together, called in by the screams and decides that the guy is crazy. ignoring all his explanations. Since this is a sarcastic comedy, in this story end all three men are left to be fools, and the pretty wife is left of okay.
If you compare this summary with the story blueprint at the top you see that it matches it precisely. There is no "story arc substitution" but an inner and an outer story coming together at the end. If you see it like that it is much easier to come up with a great storyline than to forcefully try to apply some abstract story arc substitution trick to a story just to create a turning point.