If you have a simple hash-maker the resin is usually not to pure, a simple way of refining it is to put it in a glass of cold water, stirr if needed to get the crystals to sink. The crystals will sink to the bottom and the plant matter will float, the water will turn slightly green from clorophyll, this process doesn't take long. Pour of the water slowly so the crystals stayat the bottom, if you have a very fine net(smaller than the crystal sice) you can pour it onto this. Place the crystals on a mirror(any flat glass suface is ok) and let them dry under a reading light(don't put it too close, heat degrades THC), you can also use aluminum foil, but glass is best. When it is properly dried, smoke it as it is or press it into hash. This process doesn't make for an entirely pure product, but it's alot purer than what you started with. With large amounts of resin the process can be repeated for additional purification. If you manage to "deconstuct" a piece of hash(preferably standard, since the more oil-rich types don't come apart easily) you can also use this method for purification, though I've never tried doing that myself, I allways use resin made from weed.