Add milk and yogurt to the blender, then add avocado, honey, lime juice, vanilla, ice, and a pinch of salt.
Blend on high until completely smooth and creamy, 30 to 60 seconds. Stop and scrape down the sides if needed.
Taste and adjust: add more honey for sweetness, lime juice for brightness, or ice for thickness. Blend again briefly.
Pour into two glasses and serve immediately. Garnish with lime zest or chia seeds if desired.
Notes
For a dairy-free version, use unsweetened almond milk and a coconut-milk yogurt. To make it ahead, blend without the ice and refrigerate up to 24 hours; reblend with ice just before serving.