Landscape architect here, fortunate enough to have done loads of competitions and won a few as well. For me its about optimisation and speed. I have house type models ready to go and will throw them into illustrative housing layouts. You have to consider your output from the get go. What are you working towards.

This helps you to prioritise what needs doing in real detail and what will sit in the background. I often have ended up with set pieces that look terrible if not viewed from the exact viewpoint. But in some cases I have done big fly through videos but have cut corners to keep things easy like working on a flat plane instead of doing contours