In this article I'll be discussing the basics of building a ship and the steps I go through so will start with a terminology crash course.
There are five classes of ship upgrade, from A-E inclusive with E being the "shop-floor" configuration and Class-A being the Premium Product.
The Shop Floor loadout is useful only because its cheap, and the minimum required to get your space plane flying. It serves as a reference bar for all of the refits you might do. I'd never recommend keeping your shop-floor Class-E components, because they do rather suck.
So the first loadout I'll be discussing is the slimline Class-D refit. A Class-D refit is the "default" configuration that I think about when I upgrade to a new ship. The Slimline refit replaces all of the shop-floor Class-E systems with their lightweight Class-D counterparts.
The Class-D systems are the lightest weight in their size class. There are a few exceptions to this rule, as there are ships that can utilise more than one size of component if you are trying to minimise the tonnage of your ship.
A slimline refit is cheap and will maximise your effective jump range, which is usually the purpose of the exercise. Reducing your tonnage will increase your jump range and the efficiency of your shields. I'm guessing your thrusters will be more effective too (citation needed). So its a good idea for almost any use case.
Next on the block I'd like to present the Budget package. The Class-C upgrades. A Budget Refit blindly upgrades everything to Class-C. The Class-C systems will be heavier than the Ds - but provide more of everything. The use case for the Budget refit isn't as ubiquitous as the Slimline package, but they generally weigh the same as the Big ole Class-As so it may help you plan your tonnage.
In general, I'd say go for the Budget upgrades if you don't want to spend too much on your ship. Perhaps you are a convoy Hauler and want a ship that runs well. If you are a combat ace then you probably wont see many Class-Cs in your loadout, save for a stepping stone to save power. I tend to buy Class-Cs when I have spare cash, as it feels better to have them in the ship than in the bank.
The Performance refit gives you Class-B systems throughout the ship. Class-B systems start to cost money and they add real tonnage and power consumption to your ship, but there are plenty of use cases here. Unlike the Slimline refit, I'm unlikely to pay for an entire Performance Refit in one go but will pick and choose Class-B systems. The extra weight and power draw makes them impractical for many smaller vessels, as they don't maximise for range or speed, but they do pack a punch. Miners and Escort fighters may well enjoy the Class-B luxury of a Performance refit.
And lastly the Premium refit. The Class-A. If you want to fly in luxury there is only the Premium package. A Class-A refit won't leave much power for hardpoints, especially if you have taken a full scanner package, but this isn't about putting together an efficient combat ship. This is about flying in style, class and sophistication.
More often than not, you will be mixing between classes, rather than sticking to a single set. In the next article we'll discuss the roles of ships and what they might prioritise.
Until then, fly safe.