I have a 14, a 12 and an 8 year old.
I knock on their doors, say good morning and turn their lights on at 5:55am
I have a quick shower and get dressed (takes 10 minutes)
At 6:05 I go to each of their rooms and tell them it's really time to get up now.
DD (14) goes to shower if she didn't the night before, and sometimes even if she did (12 and 8 year olds almost always stick to evening shower or bath).
I comb my hair, put my contact lenses in etc.
I go back to each room and warn them to be moving as I am going downstairs.
I go downstairs and make coffee, usually put breakfast stuff on the table and move their packed "lunch" (second breakfast) and water bottles into their bags, because I'm nice like that (if I'm on an early or not back from a night DH is on morning duty and doesn't do anything with their food and they help themselves).
The boys are downstairs within 5 minutes of me, DD sometimes spends longer doing her hair but only 5 minutes longer - she never eats breakfast because it makes her feel sick (DH is the same) but takes a snack and eats a big lunch later.
Boys (12 and 8) eat breakfast at about 6:15
Older 2 (14 and 12) leave the house at 6:30 to catch their bus - they have it coordinated like synchronised swimming, and meet same age siblings from 30 meters down the street at the end of our drive and walk together.
Dc3 (8) finishes breakfast more slowly, reads to me for 10 minutes, needs a bit of a reminder to brush his hair, leaves at 6:50 for his bus.
The older 2 are almost completely independent really, although 12 year old likes to complain about getting up I just say yep, nobody over the age of 10 likes getting up but we all have to. 8 year old is a bit scattier but moves faster...