Hi there! I am glad you like the cards. Your feedback means a lot and I hope that one day we will all see the deck published.
As for your question - I rarely draw and scan things on paper. They are mostly done on the computer. Sometimes I use copyright-free clipart or fonts or illustrations from books (again, copyright-free) and sometimes I draw them in Photoshop or Corel from scratch.
And finally, if you want to start making your own deck, you should do so. The most beautiful thing is to see images awaken from your consciousness getting alive as a Tarot card. And imagine, one day, you will use the cards for readings, and they will be the best cards in the world because you will use your creations, the images produced by your inner being. And once when you create them, interesting thing is that you can add tons of meanings to them. Once created, they develop the life of their own!
All the best!