in 121 I log per day and it looks like this

Scheduled
Buf-Ewr 1.3
Ewr-Syr 1.5
Syr-Ewr 1.5
Ewr-Pwm 1.2

I log BUF-PWM TT 5.5 and then the total landings plus the actual or night for the day and in the remarks I will put each flight number next to the corresponding leg like 3292 EWR-PWM and so on for each flight.

I used to change it only if I did a plane swap so If I flew 2 legs and swapped planes I would have 2 legs in one entry with one plane and then 2 legs with the other plane in the next entry. I no longer do that and just put the first plane and make a mention in the remarks of the swap.

I am no longer trying to meet any FAA minimums and up to 1500 hours it was more detailed, I no longer care to deal with the time it takes.