How to Fly:
1) get a easy to break block (ex. Grass, leaves)
2) place a block
3) open your inventory and make sure you can see the block you placed
4) try to break the block you placed into the inventory at the same time
5) you will know if it works when you see a duplicated set
6) take the duplicated set and build anywhere. Only you can see the block, while the others can't!
7) enjoy! I hope you liked this :3