The technique of "contagion" is to read in the "target language"* or the "target style" or your own language before writing. On the level of the unconscious mind, you are picking up the prose rhythms of the language or style you want to emulate. You can also consciously write down little turns of phrases you might want to use. I never write anything in Spanish without doing some reading of this type for a few days right before.
The model should be realistic. I could write like Guy Davenport, Geoffrey Pullum, or Gilbert Sorrentino on a good day (or a bad day for them), or at least aspire to that, but not like Samuel Johnson or Thomas Campion. I wouldn't use Galdós in this way, or Azorín, but I would use Miguel Casado. In other words, a reasonably contemporary style, not too far removed in time, that embodies the virtues you want to emulate. Don't worry about becoming a clone, because what you are imitating is not the idiosyncrasy, the quirks particular to one writer or another, but the general virtues. In most cases you won't come that close anyway!
*"Target language" is a term used both in SLA for the second language one is acquiring, and in translation theory for the language into which one is translating (lengua de llegada). I coined, myself, the phrase "target style" to mean the ideal of style to which one is aspiring, though, like all good inventions, I am not the first person to come up with this phrase. The big box store Target also claims to have a certain "style." The phrase has also been used in the teaching of music composition.