Multipurpose Room
Bioreactor
Moonpool
Scanner Room
Exterior Growbed
Indoor Growbed

OPTIONAL

Nuclear Reactor
Obsevatory
Alien Containment

The first things you should do to make your base, is build a foundation or two, this will be used for exterior growbeds, for planting flora, just for the Bioreactor, and also use the flora for crafting, like Blood Oil for benzene, Gel Sacks for Aerogel, and Creepvine Seed Clusters for Lubricant and Silicone Rubber. Then, you'll build a multipurpose room on top, and then build a hatch, and your done with the basics.

Now that you have two or more platforms, with a multipurpose room, its time to focus on power. If you are making your base in a shallow area, you can use solar panels as a temporary solution, but if you're making your base deep, the Bioreactor, Nuclear Reacter, and if you're making your base in a hot area, or near a hot area, use a Thermal Plant. If you're in the shallow area, place the solar panel on top of the multipurpose room, then enter the room, and you've solved your power problems for the short-term, but in the long term, you'll need to build the Bioreactor or Nuclear Reactor, or the Thermal Plant. If you're in the deeper areas, make sure you have the materials ready for building the Bioreactor, and make sure to already have some organic material in your inventory, then enter, construct the Bioreactor, and then place your organic material into the Bioreactor, to generate power. Now your power problems are complete.

For a sustainable base, you need a Fabricator, and for progressing in the game, a Modification Station. Place the Fabricator on one of the walls, and the Modification Station somewhere not cramped by your Bioreactor, if your still on the floor with the Bioreactor, if you've already expanded.

This is where the indoor growbed comes in handy, and if you've already visited the floating island bases, you'll have this for sure. First thing you need to do is get 8 Titanium, 6 for another Multipurpose room, above or below, and 2 for ladder going to that room. Next, you'll need to get a couple plant pots, or Indoor Growbeds, they both work, and if you have Lantern Fruit, Chinese Potatos, and Marblemelon, you can use those in the Indoor Growbeds or Plant pots for a source of food, to sustain yourself. If you've visited the Jellyshroom Caves base, you'll get the filtration system, which once you've got a sustainable source of Aerogel, you can build it, and while you can build it on the level with the Bioreactor, its more spacious on your second multipurpose room. Your food and water needs are complete.

As your inventory piles up, you'll need places to put your items, and thats where the lockers come in for the rescue. There are two types of lockers, the wall locker, containing 30 slots of storage, and the Locker, containing 48 slots of storage. The wall locker only costs 2 Titanium, while the Locker contains 2 Titanium and 1 Quartz, and if you're a organized type of person, the wall locker is for you, containing the ability to change the name of the wall locker, whilst the locker does not have that ability, but if you're a disorganized person, throwing their items into random lockers, your best pick is the Locker, also containing more storage than the Wall Lockers.

Charging Utilities are a must have for a functioning base, as the Battery Charger, it will charge the batteries of your tools, so you don't have to make new ones, and the Power Cell Charger is essential for vehicles. You don't have to put them anywhere specific, just on a wall in general.

There is no specific orientation you need to put the Scanner Room and Moonpool, as I've stated in the beginning of the guide, but if your trying to make your base as compact as possible, put both as close to your 2nd Multipurpose Room as possible, and try to connect the two, using compartments or not.

If you want a stunning view of the ocean, or a stunning view above the ocean, your best bet is the Observatory, but if you want more room for building, and decorating, the Multipurpose room is your best bet, specifically, half windowed, or fully windowed. It can include a bed in it or not, it is your decision, if you want to go full decoration, trash cans, desks, toys from Lifepod 7 or the Aurora, Posters from the aurora will work fantastically, and lab equipment on the desks will make it more decorative.

OPTIONAL CHOICES FOR YOUR BASE

A Nuclear Reactor

A Multipurpose room with a Alien Containment in it can hatch eggs, and you can make a beautiful aquarium, and can hatch an adorable, cute cuddlefish. Alien Containments can be found in the Deep Grand Reef base, but also a Databox in a Bulb Zone wreck.

Congrats, your base is complete! Now, if you want, you can expand it massively! You must provide reinforcements as you expand, and to expand, you need corridors, compartments, and multipurpose rooms, to go up, down, left, right, forward, or backwards.