Thanks, Gurunath Hari! I am glad you liked it.
As for prototyping, it really depends on what you are trying to prototype. In case of prototyping web or mobile applications, I’d recommend building paper prototypes or low-fidelity prototypes using some of the following tools:
Once, you know exactly what you want to create (after a series of iterations and user feedback sessions), you can use high-fidelity prototyping tools such as Adobe Creative Suite (Photoshop, Illustrator or In-design), Sketch or Invision.
There are a plethora of other tools that exist as well. You might find this post useful in selecting the best tool.
In case of prototyping an experience, story boarding on paper or a whiteboard is a good place to start with. You might find this post useful for the same.
I am going to write a follow-up post on this topic soon. Stay tuned!