Tutorials/Materials tactics

Some materials can be 'farmed' or made in great quantities in order to allow easy access to craftable objects.

Flint
You can easily gain flint in huge quantities by collecting gravel. Collect as much gravel as you want to obtain via flint and proceed to a safe, well-lit location (as this is a good thing to get done during the night) and place the gravel in a sufficiently large block (2 or 3 high is adequate). With a shovel equipped, dig through all of the placed gravel picking up any gravel/flint that drops. Rinse and repeat until you have used up all of your gravel. This technique can be done in proximity to a Mob Spawner trap (preferably zombies for their feathers), allowing their 'loot' to build up while you dig. Gravel blocks drop flint about 8.5% of the time.

Obsidian
When water touches a lava spring block, it will turn into obsidian. Miners use troughs to place multiple lava springs on and let the water run over them. This is explained in more detail in Obsidian.