Part of my facial expressions series. All of these LoRAs are designed to mesh well with each other and have low impact on your image framing.
Sad, unhappy expression. Much less exaggerated than the default faces generated by SD for the concept, but a lot more effective. (If you want a much more extreme or emoted sad expression I recommend this LoRA, but that one doesn't play as well with others).
Starter prompts:
<subject>, sad
For more face focus:
<subject>, sad expression