You can create Global Actions that can be used in Salesforce1. This lecture walks you through how to create Global Actions.
In addition to Global Actions, you can also create and employ object-specific actions in Salesforce1. This lecture walks you through the process of creating Object-Specific Actions.
Now that you have created actions for use in Salesforce1, it is a good idea to make them more usable for your end-users. This lecture walks you through the process of creating Action Layouts to optimize the user experience in Salesforce1
In this lecture I show you how to edit the Navigation menu in Salesforce1. We also review how a Custom Tab for a Lightning Page can be added to the Navigation menu.