Before my house was built, it was nothing more than a 1 Rai x 1 metre high island of soil. I had a truck wide slope adjacent to one corner which went to the original land level. I guess the slope must have been about 15º. After the next rainy season when I saw it again the slope had developed some water channels and was eroding.
My fix was a large lorry full of mixed aggregate which we spread over the slope filling canals and making a decent looking gravel road. We smoothed it a bit by driving my car backwards an forwards on it.
That was about 11 years or so ago. The stones are still there but invisible below a layer, added by nature, of soil and grass which took about a year or so to develop.
It's a totally non-professional approach but it works.