How to design a woodland garden?

Fairygirl

To be honest, I wouldn't do anything with that, other than securing any damaged fences, and removing any damaged or fallen tree branches when it's suitable. If you want to add paths or a little clearing for a summerhouse or anything similar, I'd wait and see how you use the area as it is, and what parts would be adaptable.

I'd concentrate on the bit you see from your house this year 

Lizzie27

I agree with Fairygirl, it looks lovely as it is and will look even more so once the existing trees come into leaf. Love the snowdrops - you are so lucky.

As you slowly get acquainted with your woodland and perhaps sit on that bench and ponder, you will probably think ' I'd quite like a little tree just there' or 'that would be a good space for an apple tree'. Do it slowly a bit at a time and just enjoy it.

JennyJ

For the first summer, it might be best to observe and see what comes up in the woodland, and just remove any obvious weeds or things you don't like. You might get brambles, bracken and suchlike depending on how "natural" it is, but you might also have native bluebells, wood anemones etc to follow on from the snowdrops.

Your fruit trees might be best at the edge of the woodland where they'll get more sun and be visible from the house, or within the fence/wall where they'll blend the garden into the woodland. I don't think you need any more large trees.

Eustace

Love the snowdrops. To me it looks like the woodland garden you want is already in place.

Fairygirl

I agree @Eustace . That's what woodlands generally look like at this time of year. 

Uff

Just read the posts from the beginning and my first thoughts were, visit a true woodland and copy that. I then got to your photographs and you already have a woodland garden that will be teeming with wildlife and different plants at different times of the year. 
My advice is to do nothing, you can rarely improve on nature in such circumstances.