If you usually do the bedtime routine with your lo, get your partner involved before the new baby comes, my DH took over bathing DS1, getting him ready for bed and reading him stories before DS2 was born, made it a lot easier when I went into hospital to have the baby and also afterwards
Get a bath support for the new baby if you want to bath them both together, keeps both hands free to stop the toddler trying to drown the baby! . We bathed DS2 with DS1 from day 1 and got both ready for bed at the same time - even though DS2 was downstairs with us until we went to bed for about the first 6 weeks it helped to start some sort of bedtime routine and from about 6 weeks old he was going to bed at 7ish with DS1 - was heaven to have the nights to ourselves after entertaining 2 all day!
Never tell the toddler to be quiet when you are trying to put the baby down for a nap - means they are 200 times louder than they normally would be (learned this the hard way!)
Keep special toys, books and snacks for only when you are feeding the baby - keeps the toddler occupied for about 5 minutes
Think of easy meals to serve the toddler that don't take too long to prepare - pasta, cheese on toast, beans on toast, boiled eggs and soldiers and pizza are all favourites in this house
I'm sure I will think of more - we have a 23 month gap between our 2 lo's and it hasn't been as bad as I thought it would be.