Old and new belong together. A mix of modern pieces and antiques never tires.
Actually use your beautiful things! I have a chocolate lab and white furniture in my living room. It took some training, but now he knows the furniture is off limits.
Separate which space is public, and which space is private. Remember, the goal here is to be functional and effective. Organizing spaces in the office could really work well on productivity. By setting office furniture such as tables and chairs properly, an effective and efficient workflow could be achieved. An expansion is also not out of the picture.