"method to reduce" is correct and usable in written English.
For example, you could use it in a sentence like this: I'm exploring different methods to reduce my carbon footprint.
The European Union and the United States have both instituted biofuel targets as a method to reduce carbon emissions.
And now our task is to develop parameters of such reductions and to design a reliable and verifiable method to reduce nuclear arsenals of Russia and United States.
The idea was to find a cooking method to reduce the loss of fat when a piece of foie gras is sauteed, and they succeeded.
Traps baited with sex-attractant chemicals, or pheromones, are a promising method to reduce breeding populations of certain insects.
One method to reduce costs is worker layoffs.
We therefore adopt the subsampling method to reduce the cost.
PAR was an effective method to reduce supported metal catalyst.
A method to reduce these transverse sensitivities is presented.
An interesting method to reduce this artifact is due to Saleem et al. [33].
One method to reduce the strength of the van der Waals attractions is liquid immersion.
The proposed scheme first use PCA method to reduce dimensionality of audio feature vectors.
