With WiFi devices becoming ubiquitous nowadays, poor wifi coverage can be very frustrating. However there are practical solutions that can greatly improve your experience.
1. Move your router to a better location. Changing the physical position of your router can make a big difference to wifi coverage. Try & avoid large metal objects between your router & device, such as pipes, structural steel & appliances.
2. Select a different channel. If multiple devices are using the same channel, coverage is degraded. Choosing the least busy channel will boost performance.
3. Add a WiFi repeater or additional access points.
4. Install a higher gain external antennae.
5. Use a enterprise WiFi Access Point solution. Most routers are designed for domestic use & have very limited WiFi capabilities. A enterprise WiFi solution gives far superior antennas & radio frequency management. It is possible to run multiple access points throughout a building & vastly improve signal strength, throughput & range.