We generally have a routine, and like others it is pretty flexible. I never restrict our daily activities because it might fall across sleep time. I do try and fit it all in but sometimes it just doesn't work like that. You asked how do we deviate? I'm not 100% on what you mean but here are a couple of examples;
* Dinner time is around 5pm here, any later and the girls start getting cranky, but if i need to deviate from that, i just give them a snack at about 4 to tide them over.
* Day sleep is generally around 12pm here, if we're our and DD2 falls asleep i either let her sleep in the pram or carrier, if we're in the car i try and transfer her but if it doesn't work out it's no big deal, she might just go to bed an hour earlier that night. Although as she's got older she transfers 99% of the time now.
* If i have an appointment over DD2's sleep time, i'll try and pop her down ealrier or keep her up and be prepared as i know she'll be a bit cranky...
* we have a dinner bath, books bed routine, but we chop and change a bit as to who does it, and we let grandparents and friends help if they are around, that way the girls respond to other familiar people at bed time. We aim for 7 but sometimes it's 8. The girls get crankier the later it gets though, so that's my incentive to stick to time if i can!

As for a new born baby and routine, i guess we kind of fell into one. The girls both fed 2-3 hourly and would sleep where ever we were, cot, pram, sling. So although the environment was always different their sleep routines remained similar. I found if i missed the tired signs and didn't put them down our day would turn to pot.

I think there is a real variance in the meaning of the word 'routine'. And i sometime think there is a bit of a stigma attached to the word. But i think you can use a routine and still practice gentle parenting.You don't have to be one of those people who have a routine that runs their life. Overall i've found that my girls respond best to a little structure in their day so that's what we aim for.