Stone bricks are decoration blocks that are shown mostly with building castles and “medieval” buildings. They also are material that can be turned into walls, slabs and stairs using the crafting table or a stonecutter.
Walls are good for decoration, and defense. They are mostly used in maps, or farm stuff for keeping entities in a certain position.
Redstone torches are important as redstone sources and are a key in certain redstone machines. They also have a darker and “redder” light source than torches for certain types of decoration.
Buckets are important for placing lava and water, and holding milk to get rid of effects. They also can be placed with water for an infinite water source.
Iron nuggets are important for making lanterns, which are a stronger light source than torches, and can be placed on ceilings.
Brick blocks are important for a material in house building. They also provide decoration for a chimney in your house.
Signs are important for labeling, and also for decoration. They are mainly used without writing, for custom spawners or protecting lava from water.
Ladders are important for decoration, and ascending/descending from various heights. They can be placed against blocks, and connected so you can climb up them. This is required when building a multiple-story house, or decoration purposes.