When choosing a router machine, there are several factors to consider. Firstly, think about the power and versatility you require. Higher horsepower routers are typically more capable of handling heavy-duty tasks and working with larger bits. Next, evaluate the adjustability options offered by different routers. Look for features like variable speed control, depth adjustment mechanisms, and both fixed base and plunge base options to ensure flexibility in your woodworking projects. Additionally, consider ergonomics - choose a router that feels comfortable in your hand and is easy to maneuver over extended periods without causing fatigue or strain.