Overhaul a shady garden - good resources?

My front garden faces north west and is split in two halves. The eastern side gets a reasonable amount of light because it's on the side of the house but the western side is very shady most of the time. There's a hedge between us and the neighbour and a tree in the road verge that contribute to the lack of light.

I've tried various things over the years but I'm fighting against a vigorous slug and snail population, somewhat clay-ey soil, and badly placed shrubs. Plants that I've tried but didn't grow or were decimated by molluscs include hostas, heucheras, sedum, moss, grass, lily of the valley, and probably others that I've forgotten.

My original idea was to create a moss lawn with stepping stones but I didn't do a lot of research and it doesn't look great at the moment. The moss is on the stones rather than the soil and everything else is dandelions and alchemilla molis! I'm about to go dig up some more clumps of weeds but I need a rethink of the whole area. Any suggestions on where to start?

 

Improving the soil is the first step - without that, clay soil will always be tricky. Loads of well rotted manure is the best solution. It breaks up the clay and improves drainage, but also prevents cracking if you get long spells of hot dry weather, and improves the whole structure and health of it, allowing you to have a better selection of planting.
It may be worth forgetting about the grass altogether, and having a gravel garden, or something similar. My front garden faces roughly north west, but it's quite open to the western side, so it's less of a problem. In the back garden, the border that has a similar aspect is full of shrubs and various perennials - including some that you mention. It was created from what was originally compacted grass, using the aforemementioned manure.
What ultimately works is also dependent on your general climate too. Ours is consistently damp, so things like Sorbus [rowan] Acteas and Camassias have no problem growing happily alongside the various other shrubs and perennials - Spireas, Fatsia, Weigela, Hellebores, Lily of the Valley, hardy Geraniums etc. Slugs are always a problem, and because the winter sare increasingly warm, they've been getting worse.
This year has been far worse than usual, so certain plants are having difficulty - but mainly large flowering clematis.

 

Yeah I'm not too bothered by grass but I would like some ground cover. I planted some vinca but it is growing quite slowly. I've tried encouraging the natural moss but I think the conditions aren't quite right.

When I bought the house it had bark chips here so I'm contemplating doing something like that again. I want to make sure there is good access for the hedge so I'm thinking about digging up the flowering quince altogether. It's a nice plant but the previous owner put it in a stupid place. I'm going to experiment with cutting the Ribes back hard and see if I can keep it smaller but flowering.

 

There's quite a few ferns that would look good most of the time, geraniums, aquilegia, penstemon and various euphorbs would too, but a lot of the other slug resistant leafy stuff just becomes a slug fest!
You can reduce the population quite considerably by going out evening time with a soapy salt water filled bucket and inviting them to 'bathe'. You might have to manually put them in as they seem adverse to doing it themselves for some reason!
It won't eradicate them completely, but it does bring the numbers down significantly

 

In my experience Lily of the Valley either likes you or it doesn’t, regardless of whether the conditions are perfect or completely wrong. I failed to get it to grow in all my previous gardens but here I inherited some and it’s happily growing in a very dry bed in full sun!

Agree with @fairygirl re improving the soil and plant suggestions. Shade lovers here which seem unbothered by slugs are Epimediums, geranium macrorrhizum, ferns, sweet woodruff, Liriope muscari, Carex Everest and Aster diveraticus. I also have lots of Welsh poppies, am sure some probably get munched but as they pop up wherever they like I can’t tell how many I loose.

 

Weirdly I have sweet Woodruff which found is way into the sunny side of the garden but my attempts to spread it to the other side have never quite worked. I might try it again though.

I spent a couple of hours this evening digging up the weeds in the shady side and moving some things around. After cutting the flowering currant back I'm hoping to get a little more light, which might help.

 

I have a meter along the house where nothing grows apart from a fern and a Vibernum Carlesii "Aurora", 1.5 - 2.5 m high, 1 -1.5 m wide, that doesn't seem to bother. Ferns love such condition and many don't mind of it's clay soil.
Woodruff is one of those that spread happily and are hard to remove. They build long roots connections under the surface and can pop up everywhere.

 

I think some shade lovers haven’t read the text books. Foxgloves, in my garden, refuse to grow in the shady parts and pop up all over my sunny beds or at the sunny edges of the shadier ones.

I’ve found that woodruff can take its time to get going. I moved some to a shady bed alongside our shed a couple of years ago. It’s sulked and refused to do anything ever since until suddenly this year it’s romping away.

 

It's weird that the woodruff is quite happy on one side of the garden but not the other. I've tried to transplant some before and it wasn't happy.

Since my last post I have dug up most of the dandelions and alchemilla molis, and made a horrible muddy mess in the process. I'm thinking about laying down cardboard and getting a load of bark chips to cover the claggiest parts and creating big borders around the edges. It's kind of what I have going on already but perhaps if I make it a bit more formal it would be less scruffy looking.