The perfect pronounciation of "ri"

I noticed some people in my evening class were all over the shop with pronouncing "ri" sounds.

I also noticed whilst talking to my postman (who I now keep tied up in my under stairs cupboard), that the best way to practice saying "ri" is to put gaffer tape over your mouth and shout "you!" emphatically.

I don't know why I keep him. I really don't!