Reboot is just switch off and on again, unless you do it via the router control panel. You don't need to wait between off and on.
If it used to be fast, and is now unreliable, it's possible someone nearby has a new WiFi which has landed on the same channel as yours. If you have a mobile device that will tell you the channel number, you can check. If necessary, access the router control panel and move it to a different channel.
Sadly Apple won't allow their users to see which channel a WiFi is on, but most other devices can display channel, or download software that will do so.
Edit: on the same channel, or within 2 - 3 channels either side is bad news. The usual 3 channels round here are 1, 6, and 13.
Last edited by Keef; 8th July 2015 at 22:53.
Reason: Added a bit.