My baby's been able to name the letters of the alphabet when pointed to since about 22 months. I don't mean recite the alphabet, but rather give you the correct name when you point to a particular letter. She also can often name several words that start with that letter. So if I show her a B she'll say 'book! ball! baby!'
At preschool she would walk over to the alphabet painted on the wall, point out a letter and proudly name it. She did this for days before it clicked with her teachers that this is what she was doing. They said they just couldn't believe that a baby that young knew her letters, so that even when she was plainly pointing to them and saying them, they didn't catch on until she started using words with it: 'B! Baby! B!'
We did like ashcox. Start with your daughter's name: "B! Look B stands for Baby!" and yours and dad's: "M is for mama! What's P for? That's right! Papa!" Use your pet's names, her doll's names, her friends - anything that carries meaning for her.
We also keep magnetic letters on the fridge and point out a letter or two while making breakfast. I also have a water based paint pen we keep in the bathtub, and every day while bathing I'll say "what word should we write today?" And she'll say 'kitty!' or whatever else she's been thinking about. Then I make a bid deal about the first letter. "Kitty! Look - a K! Kiss starts with K too! (kiss, kiss, cuddle, cuddle)"
And of course the reading of books.
Just have fun with it. Don't ever make it work. It'll all just come naturally