That's a cool idea for a build! I don't have too much for tips as I'm not as amazing as a lot of the other builders around here.
Are you building this in creative or survival?
The only other thing that comes to mind is to plan out how big you want the top to be and extend out from there. It almost seems to scale inwards (gets smaller) when it reaches the top.
Good luck with the build. I can't wait to see it built!
Planning is everything! Plan how wide you will make it, the material you will use, the design for each floor, etc. I suggest building on creative or this will be a very difficult task. Once you build the first/bottom section you will be able to make the rest of the building easy! As you can see the building gets smaller near the top and has the same design for each 'level'. When you decide how you want the first level to look like then all you have to do is repeat it, just not as wide. You also have to think about how the inside will be(if you are planning to finish the inside). You don't want the top of your building so small that it's the size of one room if do plan to work on the inside that is. Also you might need space for staircases or elevators. Also search up some more pictures/angles of the building. The better idea you have of how the building looks like, the more realistic it will look. There isn't much advice I could give you for a project like this though anyway. Just imagine you are standing in front of it and start building! Good luck!
Since it gets smaller the higher it goes you should do the same.If you can get a picture from the inside,you can even build the inside identical to the real thing.It will be just like it...only more squar-ish Good luck on the project