My LO use to nap in the sarong and sleep in cot at night. But when she turns 4mths,I decided to wean her off the sarong cos the older they get,the harder to wean. I simply let her cry all out till she fell asleep. It's tough at first,lasts about 10mins of crying,2mins looking around,then the cycle goes again. Longest last up till 1hr before she sleeps. Average about 30mins which means a lot of crying involved.
I don't care her unless she cry until vomit (yes,that bad!). Cos once carry,or pacify etc,she's got to suffer longer by training all over again. Cos she knows crying will get her to something. When I can't bear to watch,I close the door and leave her inside. Peep occasionally. But she sleep faster without seeing us. Maybe cos she wants to be carried. But night time she can sleep during her last milk so no problem.
After 4days,she almost lost her voice. But she can be pat to nap/bed without fuss. Lucky me cos my friend baby took a week to learn. After the training she can stay in pram and carrier too. Don't know why. Haha. Just that she still cannot fall asleep in pram,think too much stimulation looking around. Works for my LO but maybe not yours. Have to be very persistent & 'heartless' lah. But u get fruits of labor after. If not she go everywhere cannot sleep and very hard to fall asleep. That's y I start training when she turns 4mths. I read that below 4mths they're still new to the world and insecure,and they won't be spoilt (I give whatever she wants). But after 4mths they're more independent and will/can start to be spoilt.
U might check out
http://www.whattoexpect.com/first-year/crying-it-out.aspx