What are the key features to consider when choosing a hand-held bike pump?

When choosing a hand-held bike pump, consider the following key features:

1. Pump type (e.g. floor pump, mini pump, CO2 inflator)
2. Valve compatibility (e.g. Presta, Schrader)
3. Pressure gauge for accurate inflation
4. Size and weight for portability
5. Durability and construction materials
6. Ease of use and ergonomic design.