To demonstrate, I'll use a concept that I've had in the back of my mind - a Starfleet crew after the Dominion War as seen on Star Trek: Deep Space Nine. The core idea here is that some of the senior officers were on the front lines in the war and now have to try to return to Starfleet's traditional duty of exploration. Some of the crew may be suffering from PTSD as a result of what they went through in the war. The human element would be front and centre if this were a series.
Step 1 - Choose Era and Year
The year is 2379, a year after USS Voyager returns from the Delta Quadrant. This places the ship in the Next Generation era.
Step 2 - Choose Starship Class
I want the ship to reflect the underlying theme of people trying to adjust after a conflict. To this end, I'll take the Akira-class starship, a vessel designed to take on the Borg. The Akira comes with three talents to start, Ablative Armour (also seen on the USS Defiant), Extensive Shuttlebays, and Rapid-Fire Torpedo Launcher. The Akira's scale is 5, a relative value of ship size. The Defiant has scale 3, the Excelsior scale 5, and the Galaxy scale 6. The scale also is the ship's resistance value and total number of talents it can start with.
Step 3 - Choose Mission Profile
There are a number to select from, representing the different missions Starfleet sends its ships out to perform. The Enterprise, whether under Captain Kirk or Captain Picard, was a Multirole Explorer while the Defiant's mission was Tactical Operations. For my Akira, its former mission was Tactical Operations, but after repairs and refits, is now taking on Crisis and Emergency Response.
Step 4 - Choose Ship Talent from Mission Profile
Each mission profile provides a choice of four talents. However, the Akira-class already has one of the talents for the profile, Extensive Shuttlebays, leaving Advanced Sickbay, Emergency Medical Holographic Program, and Modular Laboratories to choose from. I'll take the EMH; the ship and crew will be expected to assist in wide-scale medical emergencies as part of their duties, and the EMH can be a help in Sickbay.
Step 5 - Choose Refits
Starships get one refit for every ten years of service the class has been in. With the Akira, that means just one. After the Dominion War, Starfleet upgraded the ship's sensors to better perform in emergencies.
Step 6 - Choose Additional Talents
The ship gets one more talent, to round out the five she has. The ship's captain managed to keep the supply of quantum torpedoes; not all emergencies are for evacuation, after all.
Step 7 - Choose Traits
Every Starfleet vessel begins with the Federation Starship trait. I'll add on Renowned; the ship served with distinction during the Dominion War. This could create issues when dealing with Cardassian vessels, or impress a Klingon captain.
Step 8 - Choose Name and Registry Number
I like theme naming when it comes to starships, though there's no basis for it in Star Trek. The Akira was named after the manga and anime Akira, so I want to keep to that idea. My decision for the name is the USS Justy Tylor, after Justy Ueki Tylor of the manga and anime The Irresponsible Captain Tylor. For the registry number, I'll grab a random four-digit number and add a 6 in front, to keep it in the same range as other Akiras that have appeared on screen. The resulting registry number is NCC-61310
Step 9 - Final Calculations
Thanks to the Ablative Armour, the Tylor's resistance gets boosted by two to become seven. Crew Support, or the number of NPCs available in a game session, is equal to the Tylor's scale, or five. The Shields rating is equal to Structure plus Security rating, for a total of fifteen (eleven from the /Akira/'s base structure, two from the Akira's base rating for Security and two from the mission profile's Security rating). Power is based on the rating of the Engines, for a total of ten.
Name: USS Justy Tylor
Space Frame: Akira-class
Mission Profile: Crisis and Emergency Response
Service Date: 2379
Refits: +1 Sensors
Traits: Federation Starship, Renowned
Crew Support: 5
Rapid-Fire Torpedo Launcher
Emergency Medical Hologram
Qualities: Versatile 2, Area/Spread
Qualities: High Yield
Qualities: High Yield, Vicious 1
Damage: 4 Strength
The Tylor is a tough ship, as expected from a class that was meant to take on the Borg. However, what the crew does with her will determine how successful the transition to Crisis and Emergency Response will be. It'll take a dedicated crew, even one trying to recover from the Dominion War, to succeed.