Remember that the further your fibre WiFi router sits from the devices, the harder it will be to pick up the signal – so select a central area close to a plug point for your router.
The higher it is, the further the signal will be carried. Think of your WiFi signal like light from a light bulb. If you put your Router on the floor, a large amount of your signal will be immediately sent to your floorboards.
Remember that walls can influence the signal, so the idea is to pick a location that minimises barriers to your most frequent fibre internet usage spots and devices.
Keep it on show. If you put your router in a cupboard, you'll reduce your Wi-Fi performance.
If you put your router in a visible location, it will be easier for the signal to travel, and it will also be easier to check the lights at a glance (to gauge signal strength and whether it is on).
Keep your router away from heavy duty electrical devices and large metal objects (TVs, microwaves, fridges, electric stoves) as these can interfere with the wireless signal.
Avoid windows as you may lose half your WiFi signal to the outside world.
It might be that your router is already installed in a less than ideal position and can't be moved, or that your home is just too large for a standard WiFi router's range. In both cases, WiFi power-line adapters or WiFi extenders can be used to boost the signal.