I don't know if i have the answers you are looking for, but...
can you wrap them during the day and put a gentle fan on them, i swear by wrapping, if we have a hot day here in NSW, i wrap my son of nearly 6mths, in a muslin wrap, and put the fan on low! I have even tied a ribbon on it, so he can watch it move with the wind as he falls asleep!
Another major sleep association my son has is the fisher-price acquarium! I only have to put the music on now and he knows it is sleep time! I realise this may be hard with twins, but maybe you could get a CD of relaxing music and play it at bed time! Soon enough they may realise this is their cue to sleep,
Best of luck,
Would love to hear more of your twins,
DD5, DS3, DS lost to SIDS at 6mths & DD6m
If you find wrapping is neccessary, try using a lighter material like muslin. My 6mth old still needs to be wrapped as she has reflux & is a 'flappy' baby. If I didn't wrap her, neither of us would ever get any rest.
Try elevating one end of the girls' cots as this should make it harder for them to travel up. I use 2 phone books under mine and she's only now strong enough to push herself upwards. I also removed the mobile above her cot as this would stimulate her, thus keeping her awake.
Try to resettle the girls when they wake with a dummy. Not everyone likes them but anything is worth a try to save your sanity. You might also call Tresillian or Karitane for advice or a residential stay to help you get them sleeping. There are private day stay clinics that you could go to for help too.
I think you've got a tough, but never-the-less rewarding, job ahead of you. I'm a twin girl myself & I adore my sister. I still don't understand how my mother did it as we also had 2 older brothers.
The very best of luck,
Peta, NSW, mum of 2 gorgeous girls
Rachel, 20mth girl + 1 on the way
Caitlin 19mths, Kiani 4mths.
Kim, TAS, 3mth twins
hope this helps
Laurelle, Carlos (nearly 3) Kobe (7 months)
Lisa NSW 5th baby