Community Tips: Reddit (r/3DS, r/NDS), Discord servers, speedrun discords for advanced tech.
Legitimate Unlocks: New Game+, difficulty rewards, StreetPass/SpotPass content.
Homebrew (Advanced): If you must modify saves, use Checkpoint or JKSM on a custom-firmware 3DS (which plays DS games via TWL_FIRM) to back up/edit saves responsibly—offline only.
Play the game as designed. The challenge is the fun.