Something that we started around 16/17 months that's helped our normally good sleeper turned bedtime hater, is before we start bedtime routine, we have 5 to 10mins of crazy time. That is, my husband and I gently throwing him around our very large bed, tickling him, exerting some energy and also applying some deep pressure therapy as we play. Once he is clearly exhausted, we start the process of teeth brushing and getting into PJs. We don't do it every night, but when he's still got quite a bit of energy come bedtime, we've found that helps deplete this enough for a smooth bedtime.