One consideration is the seasonality of the fruits that you grow. Additional fruit-bearing plants would ideally produce during gaps between the other fruit seasons so that you have a continuous harvest for as much of the year as possible. That's something that will be specific to your area though, so I can't really advise.

If you toss in any native plant seeds that you can find and then don't mow, the lawn will eventually reforest itself. (If you were in North America, I would recommend Robinia pseudoacacia.) Less work than mowing 1-3 times a year. In the beginning, pulling the grass at the edge of the clover can help a lot, and it only takes a few minutes every month or so.