How to delete a game file

It appears trade invites works differently from Dynamax raid invites. While you actively join Dynamax teams, for trade you both of you have to broadcast invitation and then wait for game to match you.

1. Get access to "Y menu". Plot will force it upon you early on.
2. Ensure both of you are in same network mode (+ in Y menu)
3. Get first badge on both consoles (maybe optional, but for me it worked after getting it)
4. Open Link Trade on both consoles (Y menu)
5. Set same Link Code on both consoles. Do not use 1111 as code or random players will connect and block your trade attempt.
6. Start trading on both consoles.
7. Quit Y menu, you cant start trade from "stamps" list.
8. Do nothing while game searches for traders, it will take 10-30 seconds
9. Once you get message about trade, double check other player info.
10. Trade.

I got it to work in Internet mode on same WiFi, successfully traded between Sword and Shield versions.

If you still have trouble with connecting, eg. not seeing invites or getting error while joining Dynamax team:

1. Save game.
2. Close game.
3. Disconnect wifi.
4. Connect wifi.
5. Start game.
6. Try Dynamax raid to confirm it works.

It seems “the code has been cracked” by someone at Polygon!

I’ve been attempting to confirm these steps, and so far it seems at least somewhat effective.

Use rare berries

We recommend using at least seven berries to yield a high-ranking curry, but less may work too, depending on your berry rarity.

Fan the flames hard, without burning the curry

The goal here is to get to the biggest size flame, as quickly as possible, without burning it. If you go one level above the right flame size, the curry will burn. You’ll be able to tell you’re doing well because not only will the pot sparkle, but Pokémon will come and celebrate your curry.

Don't spill while stirring

Just go for a nice steady stir, without spilling. You can tell you’re doing good work if you see sparkles above the pot. The spills will also make your controller vibrate pretty hard...

Aim for the light green circle

...aim for the lighter green circle on the inside.

Cook with other players or NPCs

Making curry with other people or NPCs has yielded Charizard-rank more often, simply because it’s easier to do everything we listed above with more people.