There's a mixed reaction to the difficulty level of Pokémon Sword & Shield. The always-on Experience Share makes it easier to level an entire team than ever. Fans cite this, and the NPCs' constant need to show you how to do everything, as a sign that the games hold your hand to an offensive degree. Some reviewers, however, say that new mechanics like wild Dynamax battles add a new level of strategy to the series. Whatever camp you fall in, you might appreciate this tip for creating an overpowered early game Ninetails.
Reddit user WeeSingInSillyville posted this short guide for finding Vulpix and evolving it into Ninetails in record time. You can find Vulpix near Motostoke, the games' first major town. It wanders around Route 3, the road to the left of the Budew Hotel. They're quite common in the grass, so you shouldn't miss them. Then, go back to the first Wild Area. Follow the video below to find the Fire Stone needed to evolve Vulpix.
WeeSingInSillyville notes that the Vulpix found in Route 3 range from about levels 9-12. You can evolve one as soon as you have the Fire Stone, so you can rock a level 10 Ninetails. But there's more. You can give it its strongest moves right away.
A new function in Sword & Shield is that there's a Move Tutor in every Pokémon Center. This Move Tutor also helps Pokémon "remember" moves. This lets them access moves they should know but weren't able to learn for various reasons. In Ninetails' case, it can learn Flamethrower and Extrasensory by remembering.
So bring that level 10 Ninetails to the Pokémon Center in Motostoke and talk to the guy manning the left counter. Then your level 10 Nintetails will know its best moves. All before you even fight the first Gym Leader.
It's worth noting that Ninetails is Pokémon Sword exclusive. Players of Shield get Growlithe instead. Fortunately, this trick works exactly the same with Growlithe. It also evolves with a Fire Stone and can "remember" its stronger moves. Pokémon of other types can evolve early as well. Users in WeeSingInSillyville's thread note that Lotad is a good candidate. Pokémon that evolve with a Leaf Stone can benefit as well, as one is found in the town with the first gym.
Of course, some might want to avoid this trick as it makes an arguably easy game even easier. But for those who love Ninetails, enjoy!