I think introducing some kind of sleep routine is the best advice that I can give you. Jacob has recently had some sleeping problems, but introducing a routine before sleep has really helped him tremendously. Basically this is what we do:

1. Go into his room, and whilst holding him, close the blinds.
2. Pull the chair up next to his cot and sit there with him for say 5 minutes, having quiet cuddles and kisses - no talking, just cuddle time.
3. We put him into his cot, and put him into his sleeping bag.
4. We put a nice warm blanket on him and then say "Time for sleep, love you"; kiss him on the forehead and give him his dummy.
5. Put the side of the cot up, and leave.

He is asleep within minutes........for him he sees this as a 'sleep trigger' so he knows when this 'routine' starts, what he needs to do. We have recently been to the Mother & Baby Unit down here with his sleep, and they DON'T practice controlled crying, and they believed that this routine (which we had started prior to going into the MBU) was great and should be maintained. If he wakes up under an hour, we re-settle him for sleep, and this involves some patting/rocking. They taught us to respond to the cry (as we were doing anyway)...not put a time limit on the cry, which controlled crying does.

Of an evening, our routine involves a little more to help him understand that the "big sleep" is on its way.....basically before the steps above, we have a bath, and then his final bottle is beside his cot by the light of his baby monitor...so it is nice, warm and relaxing.

We always have Jacob's room at around 18 - 20 degrees as now as well as I think he was too cold previously.

So......whilst the re-settling part of what we do for Jacob involves patting/rocking for him (if repeating the initial sleep routine x 2 doesn't work), the actual process of getting him to sleep is simple, and works every time. Perhaps you could find something that's suitable for you, DH and Yasin so that he learns to associate that little routine of events with going to sleep?