Where to find resources and other items? Answer thread!

[Matcha]

I thought I'd make a thread to help everyone out with finding resources, I haven't finished the game yet though so please feel free to add more!

As a starter, to access these areas, you have to purchase tools from Hank's Tool Store and some resources need to be processed (metal rocks for example) and the processors can be purchased from Bobo's Mom's store (e.g smelter/furnace).

Flowers - Pretty much everywhere, especially The Village, The Gardens, Dark Forest & Birch Forest. Also, if you can't find the flowers you need for recipes, they might appear for sale at the Night Market (if yours has upgraded to the point of the flower stall opening)
(flower types change each season)

Paper - Birch Forest.

Wood - Dark Forest.

Fish - Dedicated fishing spots labelled with a sign at The Docks, Dark Forest, & Frozen Lake.
The Docks spot is on a dock outside the Tako Shop, The Dark Forest spot is in the middle (go forward as soon as you enter), and the Frozen Lake spot is on the upper far left, I haven't properly explored this area so there may be more spots.
(types of fish change each season)

Dye - From fishing at the spots above. You get dyes from squeezing fish, this can be done by interacting with them in your inventory (the option will show). I've also noticed you can sometimes find dye in locations where you do the metal detector minigame (Beach & Cliffside).
Blue Fin Tuna - Blue Dye
Jellyfish - Pink Dye
Octopus - Black Dye
Rainbow Trout - Rainbow Dye
Red Snapper - Red Dye
Urchin - Brown Dye

Cat Hairballs - Cat Farm and pretty much anywhere that has cats.
Note that the Cat Farm costs $50 for 60 seconds of farming, which can be a bit costly early game. If you're looking for Golden Cat Hairballs, they often spawn in the Dark Forest. You can also purchase magic toe bean seeds from the person that comes from Mt Fugu - they spawn on the island after a certain point in the game, these toe bean seeds will grow 1 cat each plant if you keep the plot watered and they will remain in your backyard, yielding 1 hairball per day (this is after your backyard unlocks).

Rock - The Caves.

Washi Paper/Mulberry Branches - Orchard.
You have to purchase the paper presser from Bobo's Mom's store. It'll be delivered to your backyard, then you can interact with it and put mulberry branches in to receive washi paper.

Gems / Metal Bars/Rock - Metal Caves.
You can smelt metal rock into metal bars which are required for certain recipes. You can purchase the smelter from Bobo's Mom's store.

Sand - Beach. (Metal Detector Minigame - Will cost $20 each turn)

Bamboo - Bamboo Forest.

Clay - Cliffside. (Metal Detector Minigame - Will cost $20 each turn)

If I've missed anything, please feel free to add on to this thread, I know some things are obvious, but I thought this would be helpful for others!