The phrase "a touchstone for how" is correct and usable in written English.
It can be used to indicate a standard or benchmark for evaluating or understanding something.
Example: "The research findings serve as a touchstone for how we approach future studies in this field."
Alternatives: "a benchmark for how" or "a standard for how".
It's a touchstone for how they think about the world".
"It's a touchstone for how they think about the world… Ideas aren't that important to them".
The album helped launch the singer-songwriter era of the 1970s and remains a touchstone for how empathy, ordinary language and minimal detail can produce the weight of an entire novel.
The UK case and its outcome — the epitome of a tussle between a lion and a unicorn, the two animals on the UK's coat of arms (motto: "God and my right", pretty apt when considering Uber and its predicament) — have become a touchstone for how Uber's regulatory scuffles might play out in other markets.
Like the NHS in Britain, Medicare for All could be a touchstone for how people view other sectors such as education, transportation, utilities, and housing.
How they deal with this becomes very much a touchstone of how the season progresses and forms up.
Depicted in film and TV my touchstone for how shower sex "should" be the act is a steamy, seamless, and satisfying one.
While the lives of many LGBT Jamaicans remain bleak, the prominent Jamaican gay rights activist Maurice Tomlinson believes that young LGBT Jamaicans such as the Gully queens are the "touchstone for how far the movement will advance.
Apart from the fascist values of "blood and soil" (blut und boden), language has become the League's touchstone for how to distinguish friends from enemies: in towns governed by the League they are already experimenting with school courses to teach the children the Veneto or Lombard dialects.
In this passage, Wills discusses how Wayne became a touchstone for American domestic and foreign policy: Though Wayne went to great lengths to avoid military service in the Second World War, General Douglas A. MacArthur saw him as the model of an American soldier, and the Veterans of Foreign Wars saluted his "Americanism".
It explores how baseball became a touchstone for new immigrants and a way to access the American dream.
