Around 6ish months for us. We started with a soft spout sippy (Munchkin LATCH are good for babies that are new). Then we switched to a spotless sippy around 10 months. We still used our bottles for milk though.. didn't break that habit until 24m (not proud of it 🤦).
Around 6 months we switched to just sippys we use nuk so it still has the lines and now she also uses the munchkin non spill for juice