Cottage gardens are a bit of an thing. We had a lovely one at our last house, but it always seemed to be one of those type gardens where by you walk into someone else's and think that their garden is better or more developed than your own. In reality they aren't, it is just variation upon a theme.
The two photos below don't really show ours at it best, but one thing that did catch my eye when trying to find a photo was the Malus Golden Hornet. That tree which I kept cut back hard each winter, really helped frame the garden, and growing a clematis over it helped even further.
One other spect which we didn't have, but I would have liked, is an overgrown park bench half hidden by flowers. I also always fancied an old garden roller to grow something over. Don't just think about what plants you would like, try to also think about differing rustic features.