We did cry it out- it is hard, but it sooo worth it. I really do think you have to suffer through a bit to make your Little One a good sleeper for LIFE! Think of it as your duty- like tummy time.
First, you both HAVE to get on the same page. Remember NO good decisions are made at 2am- no matter if you are in a club or yelling at our spouse to help you get the baby to sleep. So decide before you even begin who is going to do what.
We started on a Saturday on the last nap of the day- 4:30ish. It was always the worst nap of the day, and then at night, she always had a couple witching hours, which were the worst.
#1 A good sound machine- the one we have also moves air around in the room- which is really great!! Love our Dohm, and it travels with us!
#2 A routine. Mostly for night time. Boob (or bottle), bath, book and bed. One thing we learned- separating food and sleep are really important. This helps when she wakes up in the middle of the night to get her back to sleep. That way she doesn't demand food when you know she doesn't need it or depend on the boob to soothe herself to sleep.
#3 Set up a plan before you start: How long will you let her cry between going in? We did 5 minutes, 5minutes, 7 minutes, 10 minutes, and then we'd do the nuclear option. Mr. Spice would set a timer. In between sets, we'd go in, pick her up, spend a minute or two reassuring her, and then put her down again.
The nuclear option for us included putting her in the car seat, putting a blanket over her to make the room darker (a pitch black room is best), and then bouncing the car seat up and down. If that still didn't work, we'd add the pacifier (the one with the hole- I'd put my finger in it and Mr. Spice would bounce her- total team effort!). The goal was to get her to fall asleep by soothing herself, and the car seat was better than getting herself to sleep in our arms.
#4 Second part in setting up a plan: How long do you want her to go before feeding her if she wakes up in the middle of the night? Sugar Bear had done two 8-hour stretches, so we knew she could do it. We started with the goal of getting her to sleep for 6 hours. I remember the first couple nights she went 5 hours 45 minutes, so I just fed her. But set a goal. When she woke up before that Jeremy would wake up and spend a few minutes soothing her and then putting her down (again, separating food (boobies) and sleep).
#4 Just go for it.
After 4 sessions of CIO and 24 hours, it was so much better. If you seriously can't listen to her cry- take a shower or let your partner be in charge and go on a walk without her.
Also soon after sleep training your Little One will be done with the 90 minute sleep cycle and will probably be ready to go to 2, 3, 4 hour routine. AKA first nap after two hours, second after three, and then bed after 4.
Another FAQ: When to switch out of a swadde? As soon as Sugar Bear turned over- I got rid of the sleep swaddle (Summer's were our favorite) and switched to a sleep sack. DeeDee's Sleep Nest came HIGHLY recommended! We love ours. I recommended getting a Medium. Sugar Bear has been growing into a Medium for over 6 months (she's still in the medium at 14 months)!
Update to answer questions:
1. Why we choose 16 weeks? Well, I was about to go back to work; Sugar Bear had done two 8-hour stretches; she had passed the 12 week/12lb mark, and we were READY!
2. How long did it take? The first 24 hours were rough, the next week was hit or miss, and then it took a month or so to really feel like it worked (it didn't help that she had her 4 month shots two weeks after we trained). I remember it taking a few months after that to just feel comfortable letting her get settled/self sooth herself to sleep. At 11 months, sometimes we can hear her crying for a minute or 2, but that is usually when she is most tired and soothing herself. I think it really is a 2 phase process. 1. The hurtle of CIO and 2. the hurtle of consistently getting her down for the whole night every night.
And Good Luck!!