No need to smoke/vape a sample mate. It's all about the trichomes. Look at the buds, particularly the leaves (I say particularly leaves because trichs caked onto leaves stand out in a huge way on some strains, my THC bomb sugar leaves appear yellow, not green due to heavy kief coverage). Is there kief/fine yellow/brown/white crystals all over the weed in question? Remember, some strains have darker kief than others. Look for those crystals and you will never be led up the garden path by purveyors of ditchweed. No crystals/trichs = no sale.
I have seen dark brown kief on Mango Dream buds, but pale yellow kief on THC Bomb. This is the single best way to know how high a given sample of buds will get you IME.
Also, smell the buds. the more pungent of a weed smell, the better. Remember, different strains can smell really different to one another without this being a sign of foul play. Still, no smell = no dice. Buds that don't have a strong smell at best do not have much in way of cannabinoids/terpenoids, at worst could already have been used in alcohol washes. Please also be careful to notice any bug spray/aerosol smell too. People can spray buds to make them look like they have crystals on them.
Finally, do not buy buds that are too damp. At best, they are improperly cured, at worst, this could be a symptom of spraying with fake crystals as well. Do not buy buds that are completely dried out, remember that properly cured buds generally still have about 15% moisture in them.
Also if someone tells you that buds are strain x, look up some photos of strain x on your phone and see if the first few consistent pics resemble the buds you are looking at.
