In the early days of DS2 being born, I did the following:
6.30 - both boys upstairs, DS2 in his cot whilst I ran the bath, got DS1 in - ran quickly to get DS2 into the bathroom, got him undressed and in the bath. After a while (depending on how boisterous DS1 was being) got DS2 out, dried him in the bathroom and put his babygro on and ran quickly to put him back in his cot. Got DS1 out of the bath, in his PJ's.
7.00 - both back downstairs, gave DS2 his bottle (which I prepared before bathtime) whilst DS1 watched TV/DVD. Put DS2 in his basket/babygym once finished feeding. Let DS1 come and sit on my knee for a cuddle and watch a bit more TV.
7.30ish - take DS1 to bed. Ds2 generally fell asleep wherever I left him within half an hour so left him where he was and took him to bed when I went to bed.
From about 4 months, DS2 was falling asleep so regularly downstairs I decided he needed to be going to bed and falling asleep there. So the bedtime routine is now the same as above but after DS2's bottle I take him to bed whilst leaving DS1 to watch tv - I take DS2 upstairs, put him in his grobag, read him a VERY quick story and sing a song and then put him in his cot and shut the door. Back downstairs for cuddles with DS1 before his bedtime at 7.30. DS2 is now 9 months old so we have been doing this for 5 months and it works really well. They are both in bed by 7.45pm and have the rest of the evening to myself.
If DH is here, things are a bit easier but the timings are still the same.
It is a busy hour or so and I know I rely on TV probably too much but it works for us
Phew - that was a bit of an epic