Microneedling & PRP: which method of applying PRP Is best? Via needle or smearing it on the face?

For optimal, multi-layer results it is best to both smear and inject the PRP after microneedling. Enhancing full thickness collagen production is the main objective which in turn gives the best results in collagen strengthening and textural improvements to the skin. These procedures are best provided by licensed Vampire physicians that are specifically trained in full thickness collagen techniques. As a side note, nonmedical personnel frequently do not inject PRP under the skin. Limiting the treatment to smearing does not provide the same quality results.

The answer to your question depends on the amount of correction you need and the results you hope to achieve. In my office, I offer the Vampire Facial, which involves topical application of the PRP prior to microneedling the area. The micro-needles allow the platelets to penetrate into the lower layers of dermis where they can produce a positive regenerative effect. 
My Vampire Facelift combines topical application of PRP with injections that go deeper into the dermal structure. The depth of this treatment stimulates even more collagen production, improving the skin at a cellular level. Because patients tend to see more rejuvenation with this approach, it is called a facelift as opposed to a facial. I encourage you to work with a board-certified plastic surgeon with expertise in PRP treatments. This doctor will be able to tailor your treatment to your precise needs and expectations for the best possible outcome.  

What  I suggest is a combination of prp injections followed or preceded by Microneedling with ppp. (platelet poor plasma)