Cities are hard to map because you have to take into account how fast players can travel on the server. If people will spend more time at slower speeds (low exp server) cities should be pretty compact with just a few tiles separating buildings. No one wants to spend 30 minutes walking through a city.
Another thing to think about is having some type of ground filler, such as, lava, water, mountains, ect. Which the city should be built around that way it looks more natural. People are naturally lazy which means they only do what is necessary and try not to do more. Here is an example of that.
You can see where the path to the building is, only what was needed to be removed from the mountain, was removed. That gives it a more realistic feel. An example of when ignoring the realistic side works is fibula on real tibia. The whole town is build above the ground, everything was man built so it is a little more square and it doesn't hurt the eye to look at. Though, if you go into the depot, in fibula you see that it was build through the terrain and it goes back to the realistic feel of the land.
The red square I added just an idea of things you could do to make a map more unique. In this case the mountain is separating there.
I am not the best mapper for sure but pay attention to the boarders of the mountain. You want to try to limit the square feeling as much as possible but not too much or it wont look real either. It takes time to master.
Another very useful tip when creating cities is to draw out a design first on paper. Think about what shops, npcs, underground tunnels, houses, and generally how big the city needs to be.
If you are filling big areas of the city with grass or something like that. It means your city is too big or not designed in a way that is realistic to what is inside the town/city.
The most important thing is you will never build a good town in 30 minutes. Ever. I can tell from your map above you are trying to work too fast. If you ever build a house with one drag of the mouse it will never look good. It takes time. The pay off for patience is 10 fold.
Last thing ALWAYS... and I mean always build the wall around your city AFTER everything inside is created. That way you can build the wall correctly and you don't have to fill in a bunch of area with useless or random stuff.