So… you know how we are always talking about phonetics in class… Well, I found this series of videos(12 of them) about the vocalic sounds in American English. If you have time, watch them all and practice these sounds. They show you how to position your lips and your tongue and they are quite illustrative. They also give you the different spellings for each sound. I am sure you’ll find this rather useful.
EOIPIEDRALAVESMERCURY 