DD settled on her own some times when she was a few months old, then went to having to be rocked to sleep, sometimes i would be in there till 9.30!!! this basically went on till she was about 12 months (from about 7 months) when we dropped the second day sleep and now she is fast asleep by 7.30pm at the latest. We do feed to sleep, but sometimes she will be happy to go in her cot after the feed and will go to sleep if i just have my hand on her tummy.
I think its a good idea to change this around a little, they grow so fast and what worked for them when they were 4 months suddenly doesnt work at 6 months. Thats what i found anyway. Good luck!