In this post and the next I'm going to show a neat technique with regard to characters. After they've interacted for a couple chapters, have them size each other up, the way I do in my science fiction manuscript, Day 10K. Below we have Kendrick, an idealistic ensign fresh out of the Academy. He's being reamed out by D'Abo, a senior lieutenant about twice his age. Keep in mind, these are both good guys.
D’Abo turned and looked up at him. “As for you, Kendrick.”
“Did someone die and make you admiral? You do not interrupt the captain. You do not contradict the captain. You can send your cute little messages questioning his orders, but don’t let that make you think you’re going to discuss ship’s policy over a cup of hot vanilla with him! Do you understand?”
“Yes, ma’am.” Kendrick observed her. Lieutenant Gwen D’Abo was the most unpredictable officer on the ship. She was a mustang -- having signed onto the Fleet as ordinary crew, then working her way up through officer recommendations, online courses, and tests administered in the field to become an officer herself. She was living proof the process produced a different kind of officer, compared to the rigorous training of the Academy -- which was an almost scientific procedure for transforming cadets into a finished product. D’Abo evidenced a casual attitude towards her duties, which never seemed to get her on the captain’s list. On the other hand she socialized more with the enlisted crew and junior officers and was more sympathetic than an imperious officer like Grayhawk. But D’Abo could also suddenly turn rigid or even outraged when a line was crossed. Puzzling.