You answered your own question
See what other people are doing or look for inspiration in real-life buildings. I then sketch out a theme on paper and hopefully the build turns out as I imagined.
Thanks. In that picture, only the bottom half was complete!
The top half was very much a work in progress.
I have since extended the pillars a little, added stained glass windows and am working on an "inlaid design" for the very top section. Thankfully it looks quite different now. Will post a pic when its done as feedback always welcome.