You can create list workflows from SharePoint lists and document libraries. You can also create site workflows from SharePoint sites.
To create a list workflow
In the List or Library tab, in the ribbon, click the down-arrow for Workflow Settings and then select Create a Workflow in Nintex Workflow.
If the Select a Workflow Template dialog box appears, you can choose to either select a template or start with a blank canvas.
To create a site workflow
Click the settings icon () on the upper right, select Nintex Workflow, and then select Create site workflow under Nintex Workflow.