Before using the headset, which was just purchased or were inactive for a long time, charge the integrated battery. Use the charger included in its kit. If it is released by the same manufacturer as your phone, in some cases it can charge the same device that phone and actually, but it is inconvenient because you will loose the ability to charge both devices simultaneously.
Please note that the Bluetooth headset from any manufacturer can be connected to the telephone of any other manufacturer (provided that such an interface it has). It is the need to ensure compatibility of equipment from different manufacturers among themselves in their time and became the reason for the development of the Bluetooth standard.
Turn on Bluetooth on your phone if it was turned off.
Look in the menu item that corresponds to the mode of connecting Bluetooth devices. For example, in Nokia: "Menu" -> "Options" -> "Communication" -> Bluetooth.
Power on headset, using, depending on its design, a button or switch. Press the headset button to reset. In some cases, it may be arranged so that clicking on it will have such as a pen. Don't put the extra effort.
Run in phone mode, search for Bluetooth devices. Find the entry corresponding to the name of the headset. Start pairing with him.
View the instructions for the headset, which you must enter the code to pair with it. If no instructions, take turns codes 0000, 1234 and 12345.
Once the pairing is done, the headset will no longer be visible to other users. It will remain so (and paired with your phone) until, until you press the reset button.
Reset the headset by pressing the respective button and perform the pairing again in case if it crashed or if it must connect to another phone.