I get DD1 to be involved with things, getting nappies, rocking the bouncer.
When DD2 is asleep I'll play with her and always point out alot how DD2 can't do..... (whatever we're doing) cause she is too little and DD1 is a big girl.
When I'm feeding I'll chat to DD1 and ask her to get out something from her toy room to show me and we'll chat about it.
I must admit tho we have been quite lucky with DD1 behaviour she adores bubs and always wants to chat to her and show her things and wants to give her her dummy when she is crying.