SkyBlock has a few custom enchantments that you may want to know about:
Beheading - When you kill players or certain mobs, their head will drop.
Flashlight - Infinite night vision when you wear a helmet enchanted with this.
Master Looter - Mob drops will go into your inventory instead of on the ground.
Slime Curse - Chance for a slime to spawn when you break a block
Slime Walker - Walk slightly faster on slime blocks.
Universal - Your tool will auto switch to the one that breaks blocks the best.
This is a list of custom recipes for the SkyBlock game mode. These can be very useful for you, especially the furnace upgrades.
Rotten Flesh to Leather
Coal to Diamond
String to Cobweb
Nether Wart Block to Nether Warts
Furnaces, Blast Furnaces, and Smokers can all be upgraded to have up to 20x speed. Just craft the upgrade and then use it on the furnace