We are practicing letter naming and beginning sounds. Keep practicing the letter flash cards with your child. Have him or her tell you the letters they see on signs and books.
Tell your child a word, have your child identify the sound he or she hears at the beginning. For example, if you said "fish" to your child, he or she woud make the sound 'fff', not tell you the letter "f". You can ask your child to tell you what letter makes the sound after he/she identifies the sound.
Also work on saying all the sounds they hear in a word- ex. fat (ffff aaa ttt)-don't worry about the letters to spell the words, just the sounds.