You can arrange your projects into different collections. With collections you can name and categorise your projects as you need, as well as marking projects as favorite to quickly find them when you re-use them often.
To create a collection of your Mojo projects:
Go to My projects tab
Find the project you want to save into a collection
Click on the top right button of the project
Click on "Add to collection"
You can save to an existing collection or create a new one by clicking on the "+" button
In My projects tab you will now see a "Collections" tab on the top right of the screen where you can access all your collections of projects.