In rust there are many ways you can build a base, but there are 2 main shapes that people use to build a base. These shapes are either square or circle most other shapes are considered to be weaker because of their uneven protection throughout the base. some shapes are considered circles still such as hexigons, pentigons and other similar shapes.

Square Bases

Square bases are refered to by their dimentions. The most common design is a 2x2(2 by 2). The 2x2 is a very flexiable base because of its ability to be expanded. Not saying that other size bases are harder to expanded but because of its size it is much easier to do so.

The amout of people that i would recommend for a 2x2 is 1-3 people and more than that and it will get crowded and difficult to move around. For 3-6 people a 3x3 is good and for 6-8 a 4x4 is good and from 8-12 a 5x5 is good and from 12-20 a 6x6 or 7x7 is good and thing larger is not needed but doesnt mean you cant build them.

This is the simple footprint of a 2x2 Base.

An example of a more complex footprint would be this.

Circle Bases

Circle bases are good but not well protected compaired to square bases and are large for the amount of walls that can protect them, the only time you would want to use a circle base is if you are building something that is larger than 3 foundations from the center to give your base the protection it needs. Circle bases can be made a few ways which result in different shapes/amount of sides. A circle base is made of 6 triangle foundations at the center and you can build out from there with either trianges or a mix of squares and triangles.

Misc.

One way people make their bases "better" are making wide gaps where they build out in either squares or triangles and build back in the oppisite foundation type to make a small gap between the foundation of your base and this so you can look through this gap when its built up to your shooting floor.

Some people build walls around their base that doesnt close off with a roof that you can get on top of and shoot at the people outside. These walls also act as a extra layer of protection and stop people from pushing into your base if you have turrets set up inside the walls.

A way to stop people from greifing your base after raiding it is by making external tc's which means you build out from you base and remove the foundations but one and place a tc on that and build back connecting it to your base. This prevents people from building in your base even after taking your tc.