You take a piece of leather and a needle and then just use the needle on the leather and there you go: a coif. This is for high level crafting.
A coifs color depends on what kind of leather it is made out of.Regular Coif - Greenish Brown
be a member and use a needle with at least 1 thread on a piece of leather. then select coif
you craft it
Rift
runescape has more total however idk if runescape has more members
At the air altar in Varrock.
Craft things....
The bestest and fastest way is to Craft Nature Runes.
The best way to get 24M is to craft nature runes.
Get rune essence and craft them at the air altar.
Buy Them at the grand exchange, craft them, or buy them from the mage guild.
Cowhides are tanned to make Leather or Hard Leather. These are then used in the Crafting skill to make various items, mostly useful to rangers. These include Leather gloves. Leather chaps, Coifs, Cowls, Vambraces, and Hardleather bodies.