Learning The R in Spanish

Trabalenguas or Tongue Twister
R con R, cigarro.
R con R, barril.
Rápido corren los carros cargados de azúcar al ferrocarril.

As I was looking it up online to confirm the spelling, I found this other one to practice the single R. Talk about tongue-twisting!

Tres tristes tigres trigaban trigo en un trigal.
Un tigre, dos tigres, tres tigres trigaban en un trigal.
¿Cuál de los tres trigaba más? Los tres tristes tigres trigaban igual.

Also found this youtube video:

It's a little long and the lady talks funny. But the part where she teaches you the R I think is helpful. She uses the word "butter" for imitating the single R sound and "put it on" (slurred fast) to do the double R sound.