The large desk and chair in the dining room make the table and chairs look very small. I agree with pp to remove them whilst you're selling.
Could you paint the fences in the front garden/drive? The total lack of colour by way of plants, pots etc is very draining. Great to have a big drive, but definitely needs separating from the house. I'd go for some really large pots or planters with quite dramatic plants. It's such a big space that just a couple of pots either side of the front door would look lost.
Also agree about the back garden. Could you relay/repoint the paving stone path? It looks a bit wobbly. How about some tall plants in pots, like eucalyptus or red robin, to place in front of the back fence to break up the view a bit.
Overall it's a lovely house, very tastefully decorated and looks spacious and welcoming. I think the fact it's so nice inside is what makes the look of the garden/drive more of a disappointment.