I like an even balance of detail and ship size. I like details but it becomes very problematic when you get down trying to make extreme little details. Comr4de's ships show this balance quite well.
Also, there must be a balance between corridors and critical rooms. I try to keep things realistic by having toilets and showers and plenty of quarters, in addition to other necessary rooms and whatnot. Corridors should go throughout the ship but have doors at some points to prevent total loss of travel throughout the ship in the case of atmospheric decompression. Turbolifts must also go throughout the ship, but space on blockland ships is limited so you have to prioritize. Also keep in mind using the biggest bricks possible to maximize hull strength while reducing lag and keeping the ship looking nice and clean. Thick hulls make for a strong ship but can make it cramped and they can be penetrated with directed piercing weapons such as beam rifle lasers. Thin hulls allow more space inside the ship but are easily penetrated, and can be easily laid to waste with radius-damage weapons, such as rockets, torcreepes and flash cannon lasers.
Also keep in mind strategically placing rooms so that it isn't easy for invaders to overtake the ship. Corridors are important for this. Fighting in critical rooms is very dangerous as equipment can be damaged and in the crossfire something very important could get hit that could even destroy the entire ship. There's alot to take into account when building ships so it's a complicated process sometimes.
