You're in the second last city of the game and the city containing the final Gym Leader. Whoo! Head west on over to the Pokémon Center. Let's heal up and stock up then explore the city!
Snowbelle City Pokemart (Right Clerk)
Before you head back outside, speak with Mr. Bonding in the west side of the Pokémon Center for a PP Restoring Power before he leaves. You can also talk to the purple-haired man nearby to hear a verse. You can them tip him. Once you're done, head on outside.
Head north past the Pokémon Center. When you reach the two houses enter the east of the two. Talk to the woman near the back of the house and she'll change the background music. You can tip her. Once you're done listening, head on outside. Head into the house next door.
If you have a Keldeo or Meloetta you can have the guy near the entrance teach them the moves Secret Sword and Relic Song. Once you're done, talk to the Battle Girl in the lounge room. She'll give you TM08 - Bulk Up . From there head on outside.
Head south back to the Pokémon Center, then follow the path taking you south then west. You'll find a Photo Spot here that you can interact with. Once you're done head north to the Gym. The man in front of the Gym will tell you that he's at Route 20 (we'll head there after we've seen more of the city).
Head west from the gym up all the stairs until you reach the bridge. Go south from the bridge and enter the house to the east. Talk with the man here and he'll teach any final evolution of a starter Pokémon from any previous generation (as well as the current one) the best move of their type. Pretty awesome right?
This means teaching Blast Burn to Fire-types, Hydro Cannon to Water-types and Frenzy Plant to Grass-types. Feel free to teach them to your Pokémon if you want. Once you're done, walk back outside.
Tip #057: When To Go All Out
Moves like Blast Burn, Hydro Cannon, Frenzy Plant, Giga Impact and Hyper Beam do massive damage, but render your Pokemon immobile for a turn. Because of this, it's unwise to spam them mindlessly. However, when faced with a tricky opponent, it could be worth giving them a surprise K.O. with one of these moves.
Once outside again, use your Dowsing Machine to find the nearby X Sp. Atk. Next, head north-west from the building to find the ramp that you can slide down. Do so and head south to pick up the item there. It's a Full Restore . Now slide down the next ramp and backtrack to the building you exited just before. Head north from it over the bridge.
On the other side you'll find a house. Walk inside. The woman there wants to trade her Bisharp for a Jigglypuff , if you have one. Outside, head west and south down the stairs. Once you're at the bottom, move east up another set and you'll reach a clothing shop after passing under the bridge. Feel free to head inside and check stuff out.
Once you're done, leave. Take out your Dowsing Machine and move south, head down one flight of the two flights of the stairs to your east then head north again between two ledges. At the end you'll find a hidden Full Heal . And that's all to do in town!
Walk back to in front of the Gym. Head south until you hit a fence then head west. Once you see stairs leading south again, follow them then continue south into the area where the snow fades. From there head east over to the entrance to Route 20 .