I want to divide the garden up to discourage the dogs from running, now three of them aren't allowed to and we can't really enjoy being out there at the moment because of it. I don't want proper hedges, just waist high planting to break up the expanse a bit! And nothing spiky please :-P

Hebe's are great shrubs - nothing harmful for the dogs and not much care or attention needed from you either.  Some varieties grow very quickly and there are all sorts of leaf shapes and colours to choose from :)

but some of the large leaved Hebes are not very hardy which might be a consideration depending on where the OP lives.

What sort of soil are you on, shade or sunny ?.

For me it's euonymus every time.  There are so many different coloured leaves to choose from.  And it doesn't shed its leaves so you have colour all year round.

Very soft, sandy soil - it's almost entirely sand from around 1-1.5ft down.  Full sun in the areas I'll be planting.

Try the RHS plant selector
[url=].  http://apps.rhs.org.uk/plantselector/  [/url]
I'm on heavy clay, soft sandy soils are a mystery to me lol.

Make sure when you have chosen plants that are suitable for light sandy soil, that you take the time initially to dig plenty of compost into the ground pre-planting.  Sandy soil drains extremely quickly and will lose its nutrients with the water making it harder for the plants to thrive :)

http://www.gardens4you.co.uk/index.php?/Garden-Solutions/Plants-for-sandy-soil.  Some nice suggestions here.

On clay here - sticky, wet, oozey stuff!