Workaround for the error "System.CalloutException: Callout from Apex triggers are currently not supported"

While working on Order Capture, there is a requirement to keep the SAP Quote Status in sync with that in SAP CRM.

I come to know that from Apex trigger, we cannot make synchronous callout to Web Service. For that I had to use Apex Trigger and make a future callout to the external Web Service.

I thought of jotting down my own steps. However, I found this blog quite elucidating to comprehend, and thereby saving my time to write down on my own. 

Here it goes:   Callout from APEX Triggers