The best shape for looks and aiding nature seems to be the cresent. Here I allowed arched strips to grow which helped the dry patches and added seed.
The white flower in the foreground is Yarrow which has many health benefits. The clump of grass behind was patchy but allowing the grass to seed one year fixed that.
When is it too much? Well it depends on personal taste and the amount of garden space. When it gets too much, it's not a problem, we can just cut it back and watch it grow again.
