The key is to remain truthful and honest, so don’t falsify information, glorifying products or services with claims that you yourself heart-of-hearts do not think to be true.
This might work in the short term but it really does not work in the long run, so don’t make that mistake.
You want the audience out there to remain loyal and committed to you, for which, it is essential that you remain as honest as possible at all times.
Of course, I am not saying you rip bad products apart (who’s going to buy it?!), so remain inclined towards positivity but in a largely balanced manner.
Also be as detailed and thorough in your reviews as possible.