Get a high quality recording of the song you wish to make the video for. Preferably it should be recorded and mixed and mastered in a professional studio.
Decide on a theme and storyline for your video. Every music video tells a story. Decide what that story is and what style you want to use to tell that story.
Storyboard your video. Draw out each scene that you plan to shoot. The drawings need not be fancy as long as you can tell what is going on in the scene.
Make a shot list. Create a list of the shots that you plan to shoot in the order that you plan to shoot them.
Scout locations. Find locations to shoot your scenes. Be sure to obtain permission to use these locations.
Recruit talent. If your video calls for actors or background models or dancers find people to fill these roles and notify them of when you will be needing them.
Obtain a camera or multiple cameras to shoot the video. HD video is preferable if it is in your budget. Make sure you have all the equipment you will need such as tripods and lighting.
Conduct the shoot. Shoot the scenes according to the schedule you laid out. Do your best to stick to schedule. On scenes where the camera focuses on the band singing, play the song on a stereo and have the band sing and play along to it in order to make sure that their lips and instruments are in sync.
Edit the video. Put the video together in a professional editing program. Be sure to color correct the footage in order to make it pop and look professional. This is done by using the three color wheel tool. Using the tool, raise the blacks and increase the saturation. Adjust the settings until the video is to your liking.