The phrase "a valid way for" is correct and usable in written English.
It can be used when discussing acceptable methods or approaches to achieve a particular goal or outcome.
Example: "Using data analysis is a valid way for improving decision-making in business."
Alternatives: "an acceptable method for" or "a legitimate approach to".
I decided I would take some business classes to see if that would be a valid way for me to make some money".
Overturning a ruling by the Illinois Supreme Court, which found the tactic unconstitutional in the absence of a reason to suspect a given motorist of involvement in a crime, the justices held that a properly established "information-seeking checkpoint" was a valid way for the police to enlist the public's assistance.
As an important heavy metal ion, copper has the negative influence on otherwise healthy individuals, so establishing a valid way for the highly efficient, sensitive, and quantitative determination of Cu2+ ion becomes an emergency in the environmental analysis.
As severity of the medical problem was not included in the questionnaire, we have to take into account that we may not compare the reasons for seeking help at either one service in a valid way, for severity is a confounding factor.
This choice, was mainly a practical one, and is recognized as a valid way of sampling for illuminating cognitive processes.
Having abandoned the symbolic stage-trappings, Bergman had to find, to invent for himself, a valid way of dealing with "the agony of the couple," as he called it.
Thus, a phylogenetic tree remains a valid way of representing the major patterns of descent for these species.
That still seems to me to be a valid way of seeing the world.
They maintain it's a valid way of raising income and exposure.
"Clearly standardized tests are a valid way of providing part of the picture," Mr. Riccobono said.
