Well, park the car over night. Adjust them in the morning at normal temps (not 10 below
). Then before you finish up, spin the wheels and recheck all the gaps.
*NOTE: not trying to be mean or hurtful*
I'm guessing that either the engine was not cool enough when you did the first adjustment and therefor were adjusting them warm. Or the screws and lock nuts are slipping causing the readings to be off. Or your not doing the readings correcty, a go/no feeler guage with the correct measurements helps alot of beginers do valve adjustments.
Within 4-5 minutes of cool time the gaps should be very very small. Heck within an hour the gap should be very very small.