TIP - Helping Toddler Build Vocabulary

My 2 yr old son is talking up a storm. Of course, it is very difficult to understand him. As I have found out with my older son, the best way to increase toddlers' vocabulary and improve their dictation is to repeat back to them whatever they said in the complete sentences.

For example:
When my son says, "Cookie" - I say to him, "You want a cookie?"
When he says, "Booboo" - I say back to him, "You have a booboo on your leg."
When he says, "Up. Up." - I say back to him, "You want Mommy to pick you up?"
I never correct him, I just "repeat" back his words to him in complete sentences.

After few months of this, I started to tell him to repeat after me.

For example:
When he says, "Mommy, up" - I say, "Say: Mommy pick me up please." When he repeats it after me(even if the dictation is not correct), I pick him up right away.

If he continues to say, "Mommy, up" then I again say to him, "Say: Mommy pick me up please". He quickly realizes that he will not be picked up unless he says it and immediately says the full sentence. After a few repeats of this routine, he automatically says, "Mommy pick me up please" whenever he wants to be picked up.