To create a custom workflow for a specific document in SharePoint, follow these steps:

1. Create a SharePoint library, if it doesn’t already exist, where you want the document to be managed.
2. Select the SharePoint library on the Ribbon and then select Library Settings
3. Under Permissions and Management, select Workflow Settings
4. Under Select a workflow, select Specify a new workflow
5. Under Select a workflow template, choose the appropriate workflow template.
6. Under Workflow name, enter a name for the workflow.
7. Under Start Options, select when you want the workflow to start.
8. Click Next, and then click publish.