The Spring Mine holds the essential ores for the upgrading of your tools to more powerful versions, such as Silver and Gold, as well as more valuable ores that allow you to create makers or accessories. The ores inside can also be shipped to provide an extra source of income at the start of the game.
It is advisable to bring a basket along, to save space in your rucksack. This will ensure that you will not only be able to make more profit, but that you will also be able to make it further into the mine.
Bring a Turbojolt and Bodigizer if possible to help with your fatigue and stamina levels. A Turbojolt XL or Bodigizer XL will help even more. If available, Elli Leaves are also a great way to help with fatigue and stamina.
Saving before entering a floor and reloading if you don't get the items you want is a great way to save on energy. It is also useful to prevent you getting stuck for not being able to find stairs going to the next lower level.
You cannot find black grass from floor 101 to 250. It is best to use the save-reload method to save any recovery items you have if you are going for the teleport stone, goddess jewels, or mythic stones.