Start with viable, correctly identified seed
Freshness, storage and dormancy differ widely among species. Some seeds need cold stratification or other pretreatment; others should be sown promptly. Follow species-specific propagation guidance, and do not assume that a bag labeled “bonsai seeds” contains a special dwarf variety. Bonsai size comes from training and container culture, not a magical seed type.
Give seedlings room to become trees
Use a clean, aerated medium and a container that drains. Maintain moisture and light appropriate to the species. Once seedlings emerge, avoid crowding and monitor for damping-off, heat stress and drying. Keep records: germination date, provenance and any pretreatment make later comparisons useful.
Build structure before miniaturizing
Early development is the time to create a useful root base and trunk line. Allow strong growth when the goal is trunk thickening; trunk chops, wiring and root work must match species and vigor. A seedling held in a tiny bonsai pot from the beginning may remain thin and weak rather than becoming a convincing small tree.
Plan for years, not a season
Seed propagation is rewarding because the grower shapes the tree from its earliest stages. It is also uncertain: not every seed germinates, and not every seedling becomes good bonsai material. If the goal is to practice styling soon, nursery stock may be a better parallel project.
Historical archive record