* The kelp forest is the best place to find leaves, though you'll be able to harvest the song cave too. Just use bind soong to pull the leaves from the ground, this won't always yield leaves, bones bulbs and berries are also common, and with some luck Leaf Poultice.
* The open waters are the best place to find eggs and small eyes. (the money and their breeders) But there is one spot inside the Mithalas Cathedral where you can hunt for money breeders even more easily. With a convenient path to an other area for them to respawn nearby. (around a whirl pool)
* The open waters little bit between the Veil entrance and the Mithalas entrance is the best place to hunt fish (beware the 2 Swordfish), untill you can reach the Veil.
* There is a Camopus in home waters, he is a bit difficult to kill, but drops 4 rubbery meat upon death, so you only need to kill him twice.
+2 heal food:
Egg+fish oil ... + rubbery meat
Leaf+meat ... +fish oil
Egg+fish oil ... + small eye
Also, once you get the hang of the game a bit more, you can avoid being wounded in the first place by sufficiently clever movement, and knowing how to deal with each enemy.