When building a custom approval workflow for Time Off/Training and other types of request, you will need to include a Require Approval workflow step on your workflow. This workflow step type will appear in the Type drop down on your Approval workflow:

You will also be given some additional options when selecting a Require Approval step type:

1. Any recipient can approve - Set to YES - This option can be used when you have specified multiple approvers on a workflow step. In the example below, the recipients on my approval workflow are the employees manager and the employees approver. With the option set to any recipient can approve, both recipients will receive an email and workflow notification and when either recipient approves the notice, it will approve the workflow step and remove the approval notice from the other recipient.
2. Any recipient can approve - Set to NO - This works the other way around with both recipients required to approve the item on the workflow step through their notices for the workflow step to progress. 

• Implication of No - This can be used to set the workflow to end if one of the approvers declines the request. You can also set it trigger another workflow or end the current workflow and trigger another workflow. This can be used for instance to trigger a workflow with an email notification informing that the request has been declined.
• Notification emails - There is a system field for request status and this will advise on whether the request has been approved or declined following the subsequent approval step. To use this system field, simply add in [request_status] into your message content or email subject line on your workflow step.

Auto-Approve

You don't need to setup an approval workflow for the process of approving. You can set it up to auto-approve with the notify only field. When setting this field to Yes, you will notice that the Type and Implication of No options disappear. This is because the notify only option takes precedence on the step and automatically approvers the item. If you have multiple workflow steps as notify only, your message content will go out as an email to your workflow step recipients and the item that requires approval through the workflow step will be automatically approved.