High-quality cannabis flowers are characterized by several factors: appealing appearance with dense, well-trimmed buds covered in crystals, a strong and distinct aroma (often earthy, citrusy, or fruity), rich flavors, potent cannabinoid content (typically high THC and CBD levels), balanced moisture content, and absence of impurities like mold or pesticides. Ultimately, the quality of cannabis flower is subjective and based on personal preference.