If you do want to use a simple meditation/mindfulness practice to help you fall asleep while lying in bed, try this:
Lay peacefully on your back with a comfortable pillow to support your head if you need one.
Take a deep breath, breathing in for five seconds, holding for five seconds, then breathing out for five seconds, and holding out for five seconds. Do this sequence three times.
Now shift your focus to breathing and circulating that oxygen to your toes. Visualize the air coming in through your nose then traveling down to your toes, and then back out (following the same breathing count above).
Next, move your attention to your feet. Breathe in through your nose and circulate the air to your feet following the same breathing count above (five seconds in, five seconds hold, five seconds out, five seconds hold).
Next, move your attention to your ankles, then your shins, then your knees, then your thighs, going all the way up your body until you gently drift away. Many people fall asleep before reaching their knees. You’ve got to experiment and find out what works best for you. Give this one a try anytime you like.