Posted: 18/01/2014 at 17:19
It all looks very wet at the moment!
4 dogs sounds a lot for a shady lawn to cope with in the wet weather. Would it be possible to fence off a bit to make them a run and cover it with something like bark over a permeable membrane to stop that bit getting muddy?
Then the other bit. If you were to make a seating area it would be best to put down some sort of surface, like paving stones or gravel, that depends on your budget.
You can get grass seed for shady lawns, it looks as though it could do with being re seeded. Would need raking over when it's dryer to make a bit of a tilth. I mix seed with compost and throw it over the bare areas in spring or autumn.
You can dig flower beds wherever you want them, round the edges or island beds, so long as the soil is deep enough and not full of tree roots. Add compost and rotted manure -if you can get it. Plant some shrubs for structure and perennials. Have a look on Google for shade loving perennials, there are quite a lot. I like some of the hardy geraniums that grow in shade and plants with nice leaves, like brunnera "Silver Frost", Hostas, pulmonarias and aquilegias.
If there is a sunny patch somewhere and you want cheap, quick results then sow some hardy annuals in Spring.