It might be more of an intermediate thought, but a list of mistakes I commonly see people make:
1) Caring about the quality of crops other than Turnips/Flax
2) Caring about animal quality, without going hyper-autistic on it
3) Putting significant effort into metal quality without access to level 9
4) Hunting anything other than whales/trolls/mammoths(early game, bones)/Moose(bones)/anglers(early game) (unless you're trying to make a sweaty PVP character/miner early world)
5) Making LARP foods(Read as: not streamlining your base around making ~10 of the best effort:FEP foods you can make)
6) Not using barterstands in almost every production line
7) Not knowing what to trade
8) Not knowing basic running techniques / that raw hide exists
9) Not knowing quell the beast exists
10) Not understanding HHP damage & caps
11) Not knowing the bots in public clients (for example Ard's pepper bot, farming bot)
12) Not knowing which credos are important(lots of cave hermits, mystics, and herders about)
13) Not knowing to test local tree growth speeds & how to decide which tree is best for them to plant based on that & their wood production goals
This is very much coming from a min/max perspective, but I feel like every day I see people wasting their time making grub pies, replanting the carrots in their quality patch, (((poorly))) breeding their goats, and studying scarab talismans when the extra 1k LP/h will literally never make a difference.
I don't intend to edit the wiki, but if anybody wants obscure information to put there, I'd be happy to help with details any potential writers are unsure about