This method has not been researched to my knowledge, but I found it effective when my oldest child was 2. You can ask your child to stay in bed, lying down, and say that you will return for a goodnight kiss. Initially, don’t leave for long, then you can wait longer and longer between visits. It can help to give a pretext for leaving such as “I’m just going to fill up your waterbottle”, or “I’m just going to help Daddy in the kitchen”.
For a detailed description of this approach see “The no-cry sleep plan” here: https://www.nowtolove.com.au/parenting/expert-advice/bedtime-techniques-for-problem-sleepers-18615 or Dr Wilsons Sleep Management Plan here: https://www.royalsurrey.nhs.uk/wp-content/uploads/2015/09/MANAGEMENT-OF-SLEEP-PROBLEMS-FOR-PARENTS.pdf.
Please add your experiences with this approach in the comments below. Please provide the age of your child when you tried it, and how long you tried it for. If it helped, please share the effects you saw. If it didn’t help, why do you think it didn’t work in your case?
With my son, when he was 2, this helped him to stay in bed long enough to fall asleep while waiting for kisses when he was tired. If he wasn’t tired though, he’d just play.
With my daughter, when she was 18 months, she would get wound up every time I left the room. It helped if I said where I was going (e.g. I’m just going to fill up your water bottle in the kitchen), but ultimately, I didn’t persist with the technique. When Beth was calm, I felt the constant interruptions were keeping her awake, and if she was upset, leaving repeatedly just made things worse.
“He got more active upon our entry to his bedroom. Even over the few weeks we tried this, he always stayed excited as we came in.” (Mother of 16 month old boy tried this for about 3 weeks and found it didn’t help)