We got a baby doll and collected a special wrap, bib wipes etc so and then dd2 with ds had their own special baby to look after. We also moved them out of the cot into a bed well before the new arrival. The last thing we did was put together a special box with books and quiet toys to play with while I was breastfeeding. In the end they would often snuggle up and just watch fascinated, or get a burpie cloth etc.