Windbreaks are essential for protecting plants in the forest garden. There is always a balance to be struck between protection and sunlight. Generally, plant the tallest windbreak to the north, less tall to the east and the shortest on the south and west.
If you can afford the space, plant a double thickness hedge, and try to avoid gaps by using baffles or overlapping hedges.
The protection offered is about 8 times the height of the hedge eg a 5m hedge protects about 40m into the garden.
To support wildlife, plant native where you can. Here are some that work well:
And these are some non-natives:
If you have the time, buy a few cultivars of your hedging plant and propagate them from cuttings. This is a cheap way to have a hedge that fruits well. See the sortable Forest Garden Spreadsheet for more windbreak species suggestions.
Use dead hedges in front of specimen trees, by the time they decompose, the windbreak hedge will have become established.
They are simple to make: put posts (preferably Larch or Sweet Chestnut as last longer) in pre-made holes with a post hammer and pile up the branches inbetween the posts.