When selecting bird mist nets, the denier (thickness of the thread) and mesh size are the most critical factors. For small songbirds, a 75 denier/2-ply or 110 denier/2-ply nylon or polyester thread is standard. The mesh size must be tailored to the target species: 16mm to 19mm for hummingbirds and small warblers, and 30mm to 38mm for thrushes or shorebirds. Additionally, ensure the net features UV-resistant coating to prevent degradation from sunlight and reinforced shelf strings to maintain the 'pocket' structure required for safe capture.