I learnt Spanish in an informal way, through speaking, and only during the last years I began to learn the basics - the grammar, and to correct many mistakes I was not aware to them.
One of those mistakes was the pronunciation of the R and the RR: I have always pronounced them in the same way, and didn't notice that for native speakers they have different sounds.
Now to get used to pronounce it correctly is very complicated: before each occurrence I have to remember how it is written, sometimes I'm not sure, and it is impossible to talk fluently in this way.

My question to the non native Spanish speakers:
How did you study to do it:
1. Did you hear how native speakers speak and got used to it?
2. Did you stop before each word till you learnt to do it fluently?
3. Do you, like me, do not distinguish between them?
4. Something else?

Do you have any practical advice for me how get used to it?