Hey there!

So firstly, I'm going to talk a bit about your terrain. It looks great! You have some nice diversion to the layers and the height of the terrain. You also have some pretty original ideas going for you, like with the spikes coming from the cliff, and the trees (I'll talk about that later)
My advice to you would be to mix in some different blocks with the stone and the grass. I can see you mixed some with the stone. The andesite works with it, however it's pretty subtle, so there's not too much of a difference. This has good qualities and bad qualities. On one aspect, it makes it look realistic, however it's not diverse enough for the palette. Think about mixing some darker blocks in with it too, maybe some cobblestone.

Next, your organics. So I mentioned before that you have some original ideas going for you, mainly the palm tree. I actually like the size of it, and the shape is pretty good, although palm trees tend to have pointed leaves, the tips of them are pointed anyway. See if you can't fix that bit up a little. Other than that, the rest of your custom flowers look really nice! And the little toadstools are adorable!

Lastly, your structure. I like the concept, and the palette you've chosen is really nice, except I think the lime wool is a little too 'bright' and contrasting. I'd use a subtle colour for it.
You're also going to need to work on your detailing a little. As far as I can tell, you understand depth and the way that works. You have a frame on your house, and your walls are one layer in from the frame. This is a nice first step. Next is to detail. A small amount of detail you can use on the bottom half of the house could be the use of cobble stairs, maybe some cobble slabs. Or you could add a little more detail to your palette by using stonebrick stairs/slabs. This breaks up the detail a little better. Don't go overboard with it though. Small houses tend to have very subtle detail, have a little fly around spawn and check out some of the smaller plots.
Also, I think the roof is nice, but there's far too many stairs. I think because you've made the roof on the same layer as the wall, you've made it difficult to transition. You probably want the bottom part of the roof to overhang from the roof, and also cut down on the use of stairs. Have a couple well placed stairs, they do work on this building, but not with the quantity you have.

Once you've done that, I think a couple more houses are in need on this plot. Maybe some little pathways leading around could be cute! :3

Good luck!
- Dutty :3