Greg Robertson has a large study group. Use it as well as a more intimate smaller group.
Get Mentors lined up (after you have your VCIX and before you start writing).
There is a Study group hosted within a Slack channel. As my comrade mentioned contact Gregg Robertson @greggrobertson5 on Twitter. You can create a study group within the Slack channel Gregg runs when you get access to the space. You will see who is defending for August and can create a group yourself. There are a number in EMEA defending. Start working with a mentor VCDX ASAP as they can assess whether your design is hitting the VCDX blueprint and scoring the maximum points. To score the most points might require a lot of rework and adding fictional components to score points across all Silos. So get started ASAP.