Clean the crack and remove any loose drywall, dust, or debris
Widen the crack slightly with a utility knife if needed
Apply drywall joint compound or spackle to the crack
Embed drywall tape over larger cracks or seams
Smooth the compound with a putty knife
Let it dry completely
Apply a second coat if needed
Sand the repaired area until smooth
Wipe away dust with a damp cloth
Prime the patched area
Paint to match the wall
Check for recurring movement or moisture if the crack returns