I have been doing Zentangle for many years, but wanted to know more about Zendoodle and doodles.  I used Sakura Micron pens for all three pieces.  The Zentangle tile on the upper left is on a standard Zentangle tile.  I used graphite for the shading.  The Zendoodle tile is on the upper right.  In this case,  I used a Zentangle phi tile that already had blue watercolor on it so I just embellished it.  The bottom piece is my doodle and it is on a large index card.  I enjoyed working on all of these!