It is up to people themselves to add items to sacrifice. We choosed the mob skulls (minus wither skulls), nether stars and ghast tears. Some people might like to sacrifice blocks of diamond, gold or iron. However, you need to consider if the items are farmable, like gold from gold farms and iron from iron farms. Since people play the game differently, it is tough to choose items that everybody would be satisfied about

To sacrifice an item, simply through it in the water, just like in the video. A hopper-minecraft picks it up through the block