So xray mining grants a good amount of stuff, but what if you fall into a cave? As far as I know you will use mods and everything(which is not vanilla and also is often banned on servers).

But there is a method that gives same profits

BOAT MINING

Materials needed:
Iron Pickaxe
Some armor+weapons with/without shield
A boat
A boat mining cave(I'll explain how to find them)
Soul Sand(for emergencies)
Door(If you do not have soul sand)
Magma Block(if you do not have any of these)+any block

Profits: 30 iron and gold per 10 minutes, possibly diamonds and/or redstone, music discs(if you find dungeons) and possibly amethyst

Boat mining caves are caves with a waterfall descending into their depths, therefore giving a two way system, first you should descend(the boat mitigates fall damage fully) with a boat.

Then look for resources and mine them(the boat will serve as a trap for mobs while mining) If the ores are underwater place a door(not efficient) or soul sand nearby or a magma block with a block near it to breathe without taking damage.

If you want to get back up make sure to place soul sand to get the boat to a high place while channeling the water right.

If you can beat the mobs without trapping them get a boat with a chest to replace minecarts

Hope this helped with earlygame mining!

Expected profits per h:

2 stacks of raw iron, 20 amethyst shards, 30 raw gold.

For endgame you should use magma block elevators that way.