FRLG provides a helpful tool that's essential for any RNG work. It's one of the best tools you'll get when starting the game. However, vblank can be tricky. Follow these simple tips for a smoother RNG experience!
RNG Methods
For stationary Pokémon: Method 1.
For wild encounters: Method H-1.
Speeding Up RNG Advances
Teachy TV
This item, obtained during the tutorial, can be a game-changer. Using it advances the RNG 313 times faster, allowing you to hit targets millions of advances away in seconds. Get comfortable with it; it will be your ally.
In-Battle
In any Gen 3 game, being in battle speeds up RNG advancement by a factor of two.