It also depends on the toungue's position. Some of my american friends have tried an exercise which works well. To best pronounce italian R you have to put the toungue just in the middle of the palate, closed to teeth, and not backside. The sound depends on the tounge's vibration. But I know chineses must make an extra effort due to the lack of that sound in their phonics. As other friends told you.... it's a matter of practise

I'm sorry to say that there is not exactly a method to pronouce it, the only way is just do more practice! Find some words with more "R" in it and read them as much as you can. For instance "Preparerebbero" "Chiacchereremo" " ripeterebbero"……

it's true that R in italian is well marked like R in spanish, but in some zone of Italy(Parma and other zone in the north) R is pronounce like french R

R should be well marked and not light as in English. in Italian,Must be pronounced as the other letters. example: rana,Roma,rollio,rullaggio etc...

let's repeat "RamaRRo maRRone" during all day or, if you prefer, say "tRentatRe tRentini andaRono a tRento tutti e tRentatRe tRotteRellando"