Gather a small bottle or tube with a tight-fitting cap
Make a tiny hole in the cap
Insert a short piece of flexible tubing or a narrow dropper tip through the hole
Seal around the hole with waterproof adhesive
Cut the tubing to the desired length
Attach a squeeze bulb or use the bottle itself as the reservoir
Test the flow with water
Adjust the hole size if needed
Ensure the cap closes securely
Clean and dry the dropper before use