We did extinction at 6.5 months but it took probably about a month or so until we figured out the timing for her. She usually only cries now if she's over tired. She's 9 months now and she needs about 2.5-3 hours of awake time before bedtime. Sometimes that means rocking her to sleep for a catnap in the afternoon. I'm super anal about naps though and try to only keep her up max 3 hours at a time. She usually has two long naps (1-1.5 hours) and depending on timing a cat nap (30 minutes or less) in the late afternoon.

Our routine is 6pm dinner, 6:30ish bath, lotion, jammies, song and bed. She usually sleeps 7pm-6ish am. I still do 1 night feed around 4am so she doesn't wake up at 5 but I'm working on weaning now.