To hide your base from xray users you are gonna have to build a base under lava! So what you want to do to do that you have to dig down so your at bedrock now go up 4 blocks and start searching around for a lava pool, once found you need to go under it but keep the blocks that are protecting you from the lava that is gonna fall on your head, now that you've done that you want to dig a room around the bottom of the lava pool, but make sure you don't destroy the block protecting you from the lava falling on your head! Now that you have dont that, only build in that room you have just created. Now the xrayers will be looking for your house but will have no chance finding it while it is under the lava pool.

How it works: Xray cant see through lava so just make sure you have lava above you! That is all.