I always temp at my normal time plus whenever Reagan woke up (I started charting when she was 4 weeks old). I noticed she tended to wake up between 5:30am and 6:30am, so I started temping at 5:00am, which fixed our issue.
I'm going to start charting once Liam is here, so hopefully he's a good sleeper.
Good luck when you do start TTC!!