The phrase "a primary method of" is correct and usable in written English.
You can use this phrase to describe something that is one of the main ways of accomplishing a task. For example, "The use of computer simulations is a primary method of studying complex systems."
Using visuals as a primary method of communication continues a longer trend towards short-form content and diminishing attention spans.
Smoking cessation is a primary method of reducing excess mortality and morbidity.
Effective contraception is a primary method of preventing mother-to-child transmission of HIV.
Without claws or sharp teeth, humans' ability to throw a stone or spear was a primary method of hunting for food.
A primary method of regulating these diverse functions is the heme-protein cross-link, an important post-translational modification.
In these industries, bolting and riveting are extensively used as a primary method of forming structural joints.
International guidelines recommend that breast ultrasound be used as a supplemental examination but not as a primary method for screening of breast cancer [ 13 - 17.
Nucleic acid amplification technique based assays are a primary method for the detection of acute hepatitis E virus (HEV) infection, but assay sensitivity can vary widely.
Importantly, dPCR measurements are performed without using any calibration agent; thus, this technique may be considered a primary method for the certification of nucleic acid reference materials.
Contact tracing, or tracking down every individual who comes in direct contact with an Ebola patient, is a primary method for stopping the spread of Ebola.
In Scandinavia the permeation-grouting is a primary method used to prevent the leakage of water into tunnels and hard rocks.
