Hi C.,
I am a huge advocate of sleep training, but ultimately you may have to try a few different things until you find what works best for your little one. I used sleep training for my youngest (who was, and still is, in the crib) and it worked great, but it seems sleep training is exponentially more difficult with a toddler out of the crib. It was for me anyway, and to my dismay, it just didn't work. Looking back, I now think maybe he just was not old enough to “get it”. When my now three year was two and already in his big bed I tried putting him back in his room every time he got up, talking to him at bedtime about being a good sleeper, rewarding him for a good night, closing the door if he “decided” to get up again after being told not to, and all the other toddler sleep training techniques. Nothing worked and none of us were getting any sleep, so changed my approach. If he wanted to come in our room in the middle of the night and sleep on the floor, we let him. We compromised, sort of. The rules were: He had to go to bed in his own room at bedtime (which oddly, was never a problem for him). He could sleep on the floor, but not in our bed, and he was not allowed to wake us up. He would bring his blanket and pillow and make himself comfortable on the floor - he did this every night at about 2 a.m. for almost a month, but in the end this approach really worked. After a few weeks, he was back to sleeping in his own room through the night. Once I stopped fighting with him about it, it was no longer a big deal. It's like, as long as he knows the option is there if he feels like he needs to come in our room, he knows it is his decision, and it is no longer a power struggle. Occasionally I still get up in the morning and find him on the floor next to our bed, but that doesn't bother me. I am okay with it since we still get a good night's sleep.
From what I have read recently, kids aren't really able to understand the concept of staying in bed until closer to age three (wish I had known that then). But, you do want them to be safe at night, so what do you do when they start climbing out? I have a few suggestions that I have come across after the fact (meaning I didn’t try them myself) in my constant search for "sleep advice". 1) Put him back in the crib and buy a canopy that goes over the top to keep him from climbing out. I had a friend whose daughter was able to climb out at 14 months old, and they just were not ready to put her in a toddler bed yet. She said it really worked to keep her contained at night. 2) Set up the Pack N Play in his room and have him sleep in that. Another fiend did this with her son (a little younger than yours - 20 months I think). The sides were slightly higher than his crib and the netting is slippery, so he couldn't get a good grip with his feet. That kept him contained until he was tall enough to get his leg over the side anyway. 3) Buy a clock with only an hour hand (not sure where you would get one) and place it next to his bed. Put a sticker over the number 7 (or whatever time you want him to get up in the morning) and tell him that if he wakes up at night, to look at the clock, and if the arrow (hour hand) is not pointing to the smiley face (or whatever the sticker is that you put on there) then he can't get out of bed yet. Honestly, your son might be too young for that yet, but you never know.