Hello guys. I have really hard time to pronounce “r” sound in the beginning of the words and double r.
E.g. Rui, Rio, Rua, carro, guerra…
In my language there’s only rolled r, like in Spanish.
First I thought it’s like French r, but it’s not, it’s stronger. French r is much softer.
The only way I can produce something similar is like this:
move tongue to position to say “h”, and then with a lot of saliva and strong air push, I get some gargling “r”.
This sounds similar but it’s not really practical. I mean I can’t have my mouth full of saliva all the time, to be ready to say “r” 
How do you actually create this “rr” sound?
Funny question but do you need saliva to produce it?
I hope all this makes sense