My first playthrough of Sword and Shield:
I picked Sobble as my starter. My team consisted of... well, my team pretty much consisted of every Pokemon that was available to me at the time. I caught every Pokemon in the route (unless that Pokemon had a higher encounter rate at a later route to save time) and rotated my team a lot. I was always severely underleveled but it was fun mixing and matching my team. I also grinded Max Raid battles a lot during the main story which gave me lots of watts and useful TRs and a ton of exp candies. After the 6th gym I decided to just have a main 10 or so pokemon to use from then on. MVP was definitely Mudsdale thanks to Stamina and tanking hits... Leon was 10 levels above me but I still beat him just because of Mudsdale.
Second playthrough:
I got two shinies so far, but I haven't even gotten to the opening ceremony yet. To be fair, I did intentionally hunt for a shiny Rookidee but it only took around 50 murder method encounters... And I just found some random shiny Nickit in a raid battle that I'm never gonna use lol.
So this time I'm actually gonna be using little cup pokemon that were introduced this generation to beat the game (pokemon that could evolve but didnt evolve from anything, like scorbunny)
My plan so far is to have Scorbunny, Rookidee, Sinistea, Cufant, and Applin. For the sixth slot, I was planning to have Impidimp for prankster dual screen support, but... it actually doesn't learn dual screens (rip). My team will have a very hard time tanking hits during late game... So my plan B is to make them all OP via Pokemon Camp! It's really fun and cute too! But maybe I'll find a Pokemon from this generation that would fulfill that dual screens role.
Scorbunny is there because it's the starter I chose and it has a really good attack and speed stat for a little cup pokemon. I even bred a Scorbunny that knows High Jump Kick because I don't know how hard the game will be if I just used LC pokemon lol so I'm trying to kind of optimize my team. (I had to level a Hitmonlee to level 44 to actually pass that move down... and I'm still at the part where I just arrived at the Wild Area)
Rookidee is there for speed control (through Tailwind, an egg move that it can learn from brilliant aura) and it's cute af lol. Sadly my shiny Rookidee doesn't have Tailwind so I have to use the regular one... I also made the poor choice of evolving the shiny one to Corvisquire.

Sinistea has a very high Special Attack stat and I love it's design. I luckily found a Sinistea in a raid battle and it's modest too! Cufant has a very high Attack stat too so it's there too (though I don't have it in my team yet). Applin is there for the memes honestly. It can be useful with Attract I guess.
Some candidates for my sixth slot include Galarian Ponyta and Galarian Darumaka. Ponyta because it's cute and provides some further coverage. Darumaka because its 90 attack stat and Hustle ability means it's gonna hit really hard. But honestly, dual screen support might be the most valuable asset for my sixth slot... Too bad Impidimp doesn't learn it (it has Prankster and its evolutions learn dual screens so that really sucks). Galarian Corsola learns dual screens and it's extremely tanky as well, but I already have a Ghost type and I don't want to replace it. Along with Ponyta, though, it's exclusive to Shield and I have Sword. A problem with Darumaka is that it's only available late into the game. I
could get one from a max raid battle, though.