On following impulse chains in your plot.
Impulse chains: links of behaviors, thoughts, and actions that flow naturally out of a pre-existing character, circumstance, and emotion.
Characters want things; they are in specific settings, and they begin any story with some kind of emotion. Once you place a character in a setting with an emotion, you have an obligation (to the reader, as well as to yourself) to follow the natural impulse chain each character exhibits.
Structurally flawed, troubled fiction results from the writer not following the natural impulse chain forged from the character, circumstances, and initial emotion.
Broken Impulse Chain (Bad Writing):
Brian loaded his blaster. Damn mushy old alien-mongers! He sighed, and turned towards the holopiece of his wife and children back home on the colony. I’ll never get there in one piece if these marauders keep shattering my ship, he reflected morosely.
There was a loud clank as the enemy ship latched on; Brian heard the whine of the hull being cut through. He ground his teeth. I’ll get those aliens!
Intact Impulse Chain (Good Writing):
Brian checked the tracking display; the space pirates were almost on top of him. I’ll have to fight them off again. He cut the engines, and drew his blaster from his hip. His wife’s waving arms blinked up at him from the holopiece. Brian reached through the images of his two children for the loaded battery he kept behind the display. He shoved away the thought of the colony, and home.
Kill the aliens, kill the aliens; the phrase went through his brain on a crazy loop. He loaded his blaster with the fresh battery, and set the dial to Organic Disintegration.
A heavy clank thundered through his ship; Brian glanced up, his upper lip curling in anger. He heard the whine of the hull being cut through. I’ll have to do repairs again, the bastards. Why can’t they use the upper hatch, like any normal landing party?
Brian went out of the cockpit, and keyed in the blast door code. Heavy lengths of metal rolled over the entrance, as Brian concealed himself in the deep shadow of a storage bay. Heavy feet thumped down into the ship; Brian lifted his blaster, and glanced around the edge of the wall.
Each character you write has an organic chain of impulses that spring from their essence, the circumstances, and the emotion you begin with. Follow the impulse chain to avoid overwrought scene transitions, slipped emotional changes, and distant, rough characterizations.