If you have a DWG, Revit, or other CAD file, import it directly into Blender or SketchUp. If you're starting from a floor plan or napkin sketch, SketchUp Free (browser-based, no install) is the fastest way to block out basic massing and room layouts before adding detail.

Apply real-world materials with the Principled BSDF shader (wood, stone, glass, concrete), then light the scene with a free HDRI from Poly Haven for realistic sky and sun lighting. Getting the sun angle and sky right does more for believability than any amount of geometry detail.

Twinmotion is free for personal use, students, and companies under $1M/year revenue — import your model, drag on materials from its built-in library, and get photoreal stills or a full walkthrough video in minutes instead of hours of manual render setup. This is the biggest genuine shortcut in this whole workflow.

Empty rooms and bare lots don't sell — add people, furniture, cars, and vegetation to give scale and life to the render. Both Blender (via free asset packs) and Twinmotion (built-in library) have free entourage assets; don't pose everything from scratch.

For final stills, Blender's Cycles renderer gives the most control over quality (at the cost of render time). For a client-facing walkthrough, Twinmotion exports video directly with far less setup than animating and rendering a camera path in Blender by hand.