Tip 69: Sing Along With a CD and Test Yourself
Play a CD of a song you know well, and sing along.
At some point in the middle of the song, hit the ‘mute’ button on your player, but try to keep on singing. After a short time, turn the sound back on, and see if you are in the same place as the original.
Do this a few times, and make a note of what went wrong (if anything). Are you good at keeping time, but terrible at staying in tune? Or vice versa? Work on those specific aspects and see if you can improve!