For a while I would work as a coder during the day, and in the evening I would work in the mines, for my son. "Dad we need more iron ore. Dad, make sure the furnaces have coal in them." Eventually my kid worked out that you can build generators, effectively coding it in MC bricks and providing infinite resources. Probably the first time he's coded something, he just doesn't know it. This made my evenings a bit less m…
TNT is used in farm designs, which generate blocks needing breaking, e.g. wood farms, cobble stone farms, dirt farms. There are two ways to get a lot of TNT for this: a) duping b) building a farm yielding gun powder (generic mob farm, creeper farm, witch farm) and duping or gathering sand
Hopper minecarts can collect items from below a magma block, which allows for easy killing zones in mob farms. Normal minecarts are sometimes used as gondolas for slime block bouncing lifts as the position of a player in a minecart is more accurate on servers. Minecarts can also be used to kill creatures via entity cramming. If there are more than 24 entitities within a block, creatures receive damage until the entity count drops. Once you have an iron farm, the minecarts and tracks become cheap.