Just passing on some of the things which helped me during flying for hour building to hopefully make the jump to CPL standard less steep! I was a modular student and did all my flight training part-time. This helped me grow as a pilot during pilot training/flight training. The main aircraft/aeroplane type I flew for hour building was PA28. I did my hour building whilst ATPL distance learning before my MEIR. I was also modular!

In case you want to skip through the video:

Departure: 0:47
Enroute: 05:37
Gen Handling/ Circuits: 08:15

Aircraft documents mentioned:
Certificate of Registration (non expriring)
Certificate of Airworthiness
Airworthiness Review Certificate (valid for 1 year)
Noice Certificate
Radio licence
Certificate of Insurance

I found  this book to be extremely helpful during hour building and also on my CPL Course: 

A Guide to the EASA CPL Flight Test – Jonathan Shooter
https://www.pooleys.com/shop/pooleys/a-guide-to-the-easa-cpl-flight-test-jonathan-shooter/

Make sure you have a diversion ruler too!!

I did my hour building with ANT Blackpool:
http://www.airnav.co.uk/