well, my dds are 3 years apart and for what it's worth we didn't do much of the stuff listed here....I was holding dd2 when dd1 met her, there were no presents either way, when bfing dd2 I was generally so knackered that I could barely summon the energy to play with dd1 (for the first 6 months at least), dd1 didn't always go to bed after dd2, so I was definitely not the perfect mother of two...
BUT it is a year on, and things are absolutely fine, they have a great relationship. In the early days I think you have to focus on surviving, and keeping everyone fed, watered, rested and amused (as much as you can). I did a lot of the following: asking dd1 to be really helpful and get the wipes, nappy etc, lots of jigsaws, cbeebies in great abundance, lots of trips out to the park/anywhere to keep dd1 occupied, all cuddling up in bed some afternoons and reading, and so on.
don't get too caught up on trying to apologise to the eldest for the presence of the youngest. imo that doesn't send the right signals. the older sibling will have to accept that they will get a bit less attention than their younger sibling for a while. do try to talk to them a lot about what you did with them when they were the same age though, and if you can show them baby pictures etc.
it really does just take time i think. 3 is still so little