If you are photographing a tall building from ground level, you point the camera up and the building looks as if it is falling over.
Instead of just putting up with this, try making it into a feature of the composition. Try aligning one side of the building with the edge of the frame (image) by tilting the camera.
Now it looks as if you want it to be like that, not just that you had no choice. Works better on modern buildings.
(In the UK it is permissible to photograph public buildings without the consent of the owner or architect. This right is guaranteed by section 62 of the UK Copyright Act. You are able to use the images for any purpose, including for commercial gain. No Building Release is required in the UK).