Schema definition - best practises

[wedobetter]

I have heard Tobie saying very often: "I can't wait to see what you'll build with this".

Well, I am not used to so much flexibility and I am trying to build a first app but am a bit confused on how best to define a schema.
Shall I use records, graph or nest everything (objects) in one big fat document like MongoDB?

I would like to understand how these 3 options compare in terms of performance?
MongoDB claims that by having all the data in one record, you just hit the DB once unlike relational databases, I guess this holds true for SurrealDB as well?

But also regardless of performance, what's your preference and why?
When would you use Records and Graphs rather than Nesting

Note I do appreciate the difference between records and graphs, you don't need to explain.
This question is purely about schema design considerations.

Thank you guys