My son is also 16 months and just in the last few weeks has switched. From what I am told, just wait for them to switch their schedule for themselves. They will know when they are ready to have just one nap. As far as that one nap, he tells ME when it is time to nap. He will be playing and start to lie his head down on the floor or any pillow or couch. When I ask if he is "sleepy sleeps", he will shake his head and say "yesssss". Surprisingly, the time that he is ready for a nap is the same time EVERYDAY! I have been told that this is normal, as long as they are ready for this switch. Just like you established a bed-time routine, we have established a naptime routine. We go up to my bed together, lie down and he flops around a while and then falls asleep and I will then move him to his own bed. The naps last about 2.5-3 hours. That being said, my advice is that not every baby is the same, so they don't start the transition at the same age, just know that it will be soon, and you need to watch your son's cues. Also, babies seem to thrive on routine, so I would suggest you also start a naptime routine that fits your lifestyle and it should make the tears lessen. If my son starts to cry instead of falling asleep, we do what we refer to as "hitting the reset button" where we will go downstairs again, let him play until he tries to lie his head down again (usually 10-15 minutes) and then try again. It usually doesn't take more than 2 times! As far as sleeping at night, my son has also started waking up again. I have noticed that his molars are starting to break through. We are sure that this is the problem for my son. We don't like to just medicate, so if crying lasts a while (like the other night), usually, I will take him down and we will watch TV (not big TV people, he rarely watches) but it calms him down when nothing else works since he will cry until he starts gagging. After 10-15 minutes, he is calm enough and we will try bed again but lately he just starts crying again. We eventually (after 3 hours of crying) tried 1/2 dose of tylenol and amazingly 30 min later, my husband brought a sleeping baby back to bed (Evan sleeps on a mattress on the floor in our room). So, my suggestion to you about this, is to check those pesky teeth!!! Hope my experience helps!