Minecraft wiki entry for Things_not_to_do, associated text: Cobwebs slow down the player, but not cave spiders. A careless player could end up stuck next to a cave spider or a cave spider spawner. The fastest tool to break cobwebs is a set of shears, or a water bucket, but a sword works quite well, albeit you get less string compared to using a shear.
Cobwebs appearing underwater in flooded mine shafts are extremely dangerous as the player may become trapped and drown. Always keep a sword, water bucket, or shears handy when traversing mineshafts.
The player should be wary of fire, as it sometimes generates near lava, which can set wooden structures on fire.
Mobs can easily lurk behind one of the mineshaft's many corners. If the mineshaft intersects a ravine, mobs may drop from a ledge high up in the ravines and attack any unsuspecting player. Be wary of mobs that may be in these blind spots.
The player should keep themselves orientated to make exiting the shaft easy, as the maze-like corridors can be confusing and disorienting. One way to help find an exit is to make several exit points.
There is no reason to drink milk when poisoned and under positive effects if the player has honey bottles, which they can drink to clear only the poison, leaving positive effects like night vision or regeneration active.