Continue to practice counting to 30. Alot of students are skipping number or when they get to 29, don't know what is next. Count in the car, at the store, on a walk, in the bath, at bedtime!! Anytime they count, they improve.
Continue helping your child identify letters and sounds. The easiest way to do this is when you read to them, point out letters and ask them what they are called. Then just ask them what sound that letter makes.