madmomma Like Dipsy said, in the early months I always concentrated on the eldest first. Once DD1 was entertained or fed or whatever I then had time to sit and breastfeed DD2 or give her a bath etc, otherwise DD1 would be whinging the whole time and then you feel so torn. It sounds harsh to not prioritise the newborn but I could usually sort DD1 quickly and easily whereas the baby might take ages to settle or feed or whatever.
I always had some Peppa Pig and Mr Tumble recorded off cbeebies and I sometimes put one on when I needed to breastfeed the baby. Usually I'd try to get her involved with a toy first but at that age DD1 had a very short attention span so it never lasted for long. I owe Justin Fletcher aka Mr Tumble a pint I can tell you! The upshot is that she now loves the TV and I have to ration it but it gave me sanity to carry on breastfeeding so I think it was worth it.
Over time I have managed to work it so they have their lunchtime nap at the same time. At first they didn't coincide at all but I gradually shifted their nap times by 5 mins here and there and eventually I have got to a point where they both sleep for 2 hours at lunch, it was what kept me sane. Two hours to mumsnet do the washing up, prep the dinner or whatever. Sadly, DD1 doesn't need the nap anymore, grrr!
In the run up to baby#2 we made the decision to get rid of DD1s dummy, we took it away cold turkey when she turned one. A friend had said that her 4 year old still had his because when he was 2 and the new baby came along whenever they tried to take his dummy away he would just steal the baby's dummy instead, or whinge. I took her advice and got rid and by the time DD2 came along DD1 thought dummies were only for babies and she has never bothered.
We also managed to get her onto beakers for her milk, she was on full fat cows milk by then. If breastfeeding hadn't been successful I didn't want her to think all the baby bottles were for her and to listen to her whinge because baby was getting one and not her. Again, just like the dummy, by the time DD2 came along DD1 was used to her 'big girl beaker' and knew the baby bottles were just for the baby.
We bought a Phil&Teds and bought the car seat adaptor for it and that was excellent. I know they get a bit of a bad rep, but ours has been excellent. Now that they weigh the same, either can go in either seat and we just do whatever suits on whatever day. We have had an awful lot of use from it. I've had a few people say things like ' well, I never needed a double buggy ' with raised eyebrows but I just laughed and said DD1 couldn't walk when DD2 arrived so I could hardly insist she walk everywhere!
The down side was, like someone else said, that I can barely remember the first 3 months or so at all, its a total sleep deprived blur so take lots of photos to look back on. I was so busy I just never got the time to just really enjoy my baby the second time round and now I wish I had ignored the washing up/hoovering a little more and had a few extra cuddles tbh.
Sorry to everyone else for the rather long post!