Many people (I included) want to make competitive maps when starting out. And I just want to say, it's a LOT harder than it looks. Every playspace in CP_Process has been thought about meticulously, every place has a reason to be there. If you wanna see a map that takes a formula and runs with it, Look at Cp_Sunshine in comparison to Cp_Process, a lot of the set piece areas are similar. Study how these maps work and what makes them good, while thinking about what you as a competitive player are doing at any given time.
When you rocket jump up to the crates, why do you do that?
When you take IT instead of Sewer why do you do that?
When you push door 1 instead of roller why do you do that?
Think about the advantages and disadvantages that each pathway brings and how teams might play around your areas given an ubercharge disadvantage / advantage.
For example with Uber advantage, people usually sit between the ramp and choke on badlands 2nd, and with uber disad, they would sit at Greybridge. Look at each area and why people would sit in these areas, with disad you want to have an easy escape route, and be preferably near a health pack for if you do take damage. With Advantage, you want to sit closer to your choke and intimidate your enemies, spamming the with confidence and forcing them to move back and give up an area through fear of losing ubercharge (Doesn't work in ozfortress due to the gunmettle update changes to weapon pickups, however.)
Also you might want to look at these;
Valeria's guide to competitive mapping!
Common TF2 mapping mistakes and how to fix them