I always struggle with this. Too many red and black cables and never sure where to put them. But here is a diagram which works, every time (for me anyway)
Please, be safe. Ensure electrics are switched off before commencing work – and test the wiring to ensure it IS off.
This image was found at practicaldily.com but in my experience, things don’t stay around forever, so I have a copy here.
Original link… https://www.practicaldiy.com/electrics/lighting-wiring/light-wiring-loop.php