More damage

1 Weapon + 1 Teeth + 1 Tree Sap

More damage+

Add glass shards.

1 Weapon + 1 Booze + 1 Tree Sap

More speed

1 Weapon + 1 Feathers + 1 Tree Sap

Burning weapon

Add cloth to your weapons and set them alight

1 Weapon + 1 Cloth

Burning weapon+

Add booze (after cloth, as a second upgrade) to triple burn duration and slightly increase light intensity

1 Weapon + 1 Cloth + 1 Booze

Upgraded spear

1 Spear + 2 Cloth + 3 Bones

Incendiary spear

Burn targets when spear is thrown. One time use. Use the upgraded spear in the recipe.

1 Spear + 1 Booze + 1 Cloth

Fire arrow

Multiple arrows can be upgraded at once with a single bottle of booze

x Arrows + 1 Cloth + 1 Booze

Poisoned arrow

Poisoned arrows (can be batched) (Poison lasts longer but does smaller damage per tick than fire)

Poisoned players can cure it with aloe vera.

Enemy movement is slowed and damage output is reduced for a short time

x Arrows + 4 Twinberries

... or using poisoned mushrooms.

Bow set ammo

None will be consumed, sets which arrows are used first by the bow

1 Bow + 1 Arrows

Limit to the total amount of upgrades per item. Currently set to 30 for all weapons. You can choose to have either 30 teeth or 10 teeth + 20 Feathers, or 10 teeth + 10 Feathers + 10 booze etc.

You can attach 10 parts to a weapon at once.
Example: 10 feathers/booze/teeth + 10 tree sap + weapon

Stone Axe