You could do walking meditation or you could just meditate while doing something (a sport, painting, cooking, washing dishes, doing the laundry, etc.).
If you are really busy, there is one more meditation that you can do:
If you don't have time to meditate consistently, then make a habit of going to bed 10 minutes earlier. Prepare as if you would go normally to sleep. Lay in your bed. Lay on your back, legs a little bit separated, hands on your sides, some 10-15 cm from your body, fists opened, palms on your bed, fingers spread. In this position you won't fall asleep immediately because it's not a comfortable position to fall asleep.
Once you are in position, empty your mind and meditate for 5-10 minutes (if you fall asleep before 5-10 minutes, there's nothing wrong with it, just go with it). Then turn in your favorite position and fall asleep as you normally would.
Repeat the above for a few days. Then, do the same, but don't change position to your favorite position. Just lay on your back and meditate until you fall asleep.
The later you fall asleep the better as your meditation session will be longer. Don't worry, you won't feel sleepy when you wake up because your mind will rest during meditation.
Meditate as described for as many days, months as you wish. If you wake up during the night and can't sleep, meditate as described. If you take a nap during the day, meditate as described. Also, try to meditate a few minutes immediately after you wake up. Just lay in your bed and feel your mind relaxed and empty. Enjoy.
While doing this kind of meditation, before you fall asleep or immediately after you wake up, you will notice many unusual sensations arising in your body. You could hear things, see colors, feel vibrations, have lucid dreams, fly, travel to other dimensions. If it happens, don't worry, don't intellectualize, relax and enjoy the experience.
Once you get comfortable meditating as described, you will realize that there is something in you that is yet unknown. The unusual experiences will confirm you the existence of this yet unknown "you" or "something". This will hopefully motivate you into exploring this yet unknown "you" and you will move to sitting meditation spontaneously.