The phrase "a useful form of" is correct and usable in written English.
You can use it when describing something that serves a practical purpose or function in a particular context.
Example: "This app provides a useful form of communication for remote teams."
Alternatives: "a practical method of" or "an effective means of".
Case-study is thus a useful form of research in such circumstances given that they can be used, 'to investigate a contemporary phenomenon within its real-life context, especially when the boundaries between phenomenon and context are not clearly evident' (Yin 2003, p. 13).
For Mr Mallya cricket is a useful form of marketing.
There's nothing unusual about partisans of the Bush administration defending waterboarding as a useful form of "enhanced interrogation".
The corporate letter is a useful form of storytelling and of self-definition, but modern leaders of companies have other tools at their disposal.
A very different sort of catalyst, consisting of chromium trioxide dispersed on silica-alumina, performs similarly in polymerizing ethylene but cannot produce a useful form of polypropylene.
But studio supervision, a useful form of quality control on mediocre filmmakers, risks diluting the distinctive qualities of unusually gifted filmmakers such as Trank, regressing to the mean without fulfilling the norm.
Thus, the conversion of the renewable energy to a useful form is one of the most challenging processes and natural convection plays an important role in the conversion.
Better, perhaps, to teach a more useful form of thinking.
"It provides a very useful form of non-verbal communication and would have been of immense help to early hunters.
However, despite the short-term thrill, he doubts that "destructotherapy" is a genuinely useful form of anger management because it does not solve underlying issues.
First, part of the fiscal cliff deal involved letting the Obama payroll tax cut — a significant, useful form of economic stimulus — expire.
