Because we already had children, DD2 has just sorta slipped into their routine - but she feeds every 4 hours during the day. I have found that she has to go back down to sleep no more than 1.5 hours after waking - and if she doesn't have enough sleep, I will put her in the sling to get another 20 minutes out of her, or else she just grizzles and doesn't finish her bottles, and the whole day is just out of whack.

So her usual routine is:
Up at 6.30am and fed
back down at 8.00am
She usually wakes at 9 - I'll put her to sleep at 10 again
Wake up and bottle at 10.30
Back down at 12 for about an hour - maybe more
another feed at 2.30
Down again at 4 for an hour if I'm lucky - usually 20 minutes though
If she's grizzling at 5.30, back in sling for another nap
Bath at 6.15
Bottle at 6.30
bed at 7/7.30.

She has a bath at the same time as the other two, which makes it easy. But yeah, definitely the key is getting her sleeps right - up no longer than 1.5 hours or else she turns into a horror to get to sleep and sleeps for hardly any time at all. Harder to settle an overtired baby for the rest of the day if you don't get that first sleep right!