Speak to your preschooler's teacher to find out the school's system of teaching how to write the letters of the alphabet. For example, does the school use upper case or lower case, to begin. Follow the same system to avoid confusing your child.
Set up a large alphabet chart at home and point to the letters as you sing the alphabet song. Have your child repeat after you until she is able to sing the entire song without running the letters together. Ask her to slowly enunciate each letter to confirm that she knows each one is distinct. For example, a common error is to say "elemeno" instead of "l," "m," "n" and "o" separately.
Introduce your preschooler to alphabet books that have the letters in large print along with pictures of objects that begin with each letter. Allow your child to flip through the pages and point out objects for each letter of the alphabet.
Play alphabet games where you call out a letter and ask your child to think of words that sound like they begin with that letter. Provide her with a new word to learn, using objects around the house or things she regularly sees on TV. For example, if her alphabet book says "B is for Ball," you can teach her that "B" is also for "balloon, butterfly, baseball and birthday".
Use worksheets that have dotted lines on which your preschooler can trace. Show her how to join the dots without letting go of the pencil in between. Help her do this by guiding her hand at first, then have her do it by herself.
Buy books that have space to draw shapes within two horizontal lines. Encourage her to reproduce various shapes within those two lines. Allow your child to practise such controlled movements before you teach her to write the letters of the alphabet.
Use opportunities like a visit to the beach or playing in the sand box. Teach her the alphabet by writing in the sand. Trace out the letters, saying each one out loud. Hold her hand and repeat the movement a few times, then ask her to do it by herself.