Cut an opening 1/4" wide on a tube of latex or acrylic caulk and insert the caulk into a dispensing caulk gun.
Stand on a step stool or ladder so that you can comfortably reach the fine ceiling crack that needs repair.
Slowly insert the caulk into the crack while using your finger to follow along with the tip of the caulk gun. Manipulate the caulk so that it fills the fine crack.
Wipe off any extra caulk from the ceiling with a dry paper towel.
Dampen another paper towel and use it to wipe any remaining caulk residue that isn't located within the crack.
Allow the caulk to dry for 24 hours before applying a coat of primer sealer paint.
Once the primer has fully dried, apply a layer of latex paint over the repaired area.