Just being nosey....... who are all these folk in your garden? How many kids do you have?

Do you want low maintenance? Keep as is.

Do you want to grow fruit/veg?

It was a recent kids party, hence huge number of kids running around.

Not sure growing fruit is on our list

At present it's just one big lawn with not much else going on.

Garden is west facing and gets sun for most the day, particularly the north side. High trees and hedge provide some shade on south side.

If it were me I would want to use the whole space rather than sit by the house looking out at it.
I would want a patio in the sunniest part of the garden wide borders that disguise its long rectangular shape, statement trees that focus your eye and give height to the space, I would want paths and the lawn to meander down the garden rather than it look like a football pitch, I would want a decent sized play area for the kids with soft bark to minimize inevitable scrapes. I would want an intercom between the play area, the tennis courts, the patio and the house for convenience. I would also want garden lighting to appreciate its size at night, a large hidden shed for all the garden cushions and maintenance equipment and I would want an irrigation system so I wouldn't have to spend hours with a hose.
How you achieve this depends on budget but I would get a designer to help you come up with a plan, then a landscape gardener/ builder for the hard landscaping and water and electrics. Lastly a planting scheme or someone to source mature plants will give you a polished final look.

Hi Alex

A blank space - and a great one too! West is best so you are going to have a lot of options, not only how you'd like to use the space, but also so many plants, trees and shrubs are going to love your space. My advice is to sit down with a cold beer/chilled glass of something nice and imagine yourself in that space and how you'd actually use it.

If you aren't a keen gardener, you do probably don't want high maintenance. Grass needs cutting at leat once a week in the growing season, so if you'd rather be doing something else, think more about different hard landscaping options.

Gardens really need some thought as although they are cheaper than interiors (by and large) per square foot, they can also be extremely disruptive to put right if you decide you don't like your new paving/garden studio/shed somewhere down the line! A pink interior wall you hate can be repainted easily - gardens have to be dug up!

Beth Chatto famously created her garden garden out of an area of old car park, so your tennis court might be perfect for a low maintenance drought garden. Could be modern or traditional - whatever makes you happy. Remember your garden is there to please no-one else but you...

Feel free to get in touch for advice. Lucy