2.5 What’s the best location for the router?
Try, whenever possible, to move the router closer to the location from where you connect more often.
If you connect via Wifi from all around the house, put the router on a centric location, more or less high (like a shelf) and without elements that reduce the coverage (metallic shelves, walls, columns, etc).
It’s recommended to move the router away from wireless phones, microwave devices (yes, the one in the kitchen!) and other Bluetooth wireless devices (like audio and video devices) that could cause interference.