1. **Modeling the Shape:**
- Import the reference image into your 3D software as a background or reference plane.
- Use basic shapes like spheres or cubes to block out the general form of the object.
- Apply a subdivision surface modifier to smooth out the shape and make it appear more rounded and soft.

2. **Creating the Inflatable Look:**
- Add a displacement modifier or sculpt the surface to introduce subtle irregularities, making it look like it's filled with air.
- Use a cloth simulation or manually sculpt to add gentle creases and folds, simulating the fabric texture of an inflatable object.

3. **Texturing:**
- Apply a matte material with a soft, smooth texture.
- Use a fabric texture map to add subtle stitching details and enhance realism.
- Adjust the material's roughness to achieve a soft, non-reflective surface.

4. **Lighting and Rendering:**
- Set up soft, diffused lighting to create gentle shadows and highlight the volume of the object.
- Use an HDRI map for realistic ambient lighting, if available.
- Position the object on a clean, minimal background with a light gray or pale blue color to maintain focus on the object.

5. **Final Touches:**
- Render the scene at a high resolution to capture all the details.
- Post-process the image in software like Photoshop to adjust levels, contrast, and add any final touches.

By following these steps, you can create a high-resolution 3D render that matches your description. If you need further assistance with specific software tools or techniques, feel free to ask!