One of the most easy to use tool from Adobe Illustrator, but with a great effect, is the 3D rotate tool, from where you can pick the isometric rotation.

Start with a basic square shape, copy  / paste / duplicate 3 times and apply for each a different isometric rotation (top, left, right). Those will be the faces of your cube.

Now, select all your faces and go to Objects / Expand Appearance to can manipulate them more easy. Align them in shape of a cube like you saw in the first screenshot of this tutorial. Let’s assume you want to make a multicolor vector cube icon. Using few basic perspective rules, duplicate your cube. Is easy, because you just need to follow the cubes lines. In center of your cubes is formed a star shape what is like a control shape, to assure yourself that the cubes are aligned properly.

Use 3 color tints for cube faces. One for most exposed faces (light), two for shadow / dark faces.

Another beauty of this fantastic tool, is that you can create so easy patterns for your website backgrounds, wallpapers etc. Using same steps describes above (square / isometric effect / cube) you can create a seamless cubes pattern. Align each cube close to next one on vertical and horizontal, add a clipping mask for a certain portion like in next screen and you got the pattern.

Here is an example of pattern  just created.

What about a vector logo? Nothing more easy after you understand the idea of isometric tool. You can apply a lot of effects for cube faces. Light lines can give a more sharp  / contrast visual effect of your cubes.

Feel free to explore the endless possibilities of 3D rotate tool from Adobe Illustrator with its isometric effect.

Once you have your logo, put it on these promotional products to promote your brand.