So... these are some things that you can build on your skyblock. (Not including stuff like a cobble generator) I will put discriptions under some of them.

1. House with Storage

2. A Mob Spawner/Trap
-Look it up on like YouTube or somewhere else

3.Snow Farm
-A snow golem in a 1x1 area, and you just keep shoveling (is that a word??) the snow that it creates on the block its standing on.

4. An Iron Golem Farm
-To get all the iron you need
-Again look it up (its too hard to explain here)

5. massive farms (maybe some of them automatic)
-Cactus
-Wheat
-Carrots
-Potatoes
-Pumpkins
-Melons
-Sugarcane (have i missed anything)
-Nether Wart

6. Semi-Automatic Cobble Generator

7. Mushroom Farm

8. Animal farms
-keep one block of grass in the beginning and let it grow in a cage, animals will spawn (hopefully)

9. Tree Farm

10. Obsidian Generator
-this one is pretty good https://www.youtube.com/watch?v=7gZ68bxTrss (if you can click this link)


If you have anymore suggestions leave them in the comments and i will add them asap.