I'm a girl, this will be from a girls point of view:
1. Set the mood with some lighting.
Redecorate your room somehow.
2. Make yourself a treat
or make a romantic breakfast, for yourself.
3. Write yourself a love letter.
Or write '10 things I hate about you'.
4. Get on Omegle or Chatroulette with some ice cream
5. Reflect over why you might be single, while in a hot tub.
You don't have to shave. (Optional: Get stupid substance)
6. Take a hike or a romantic walk by yourself.
Howl at the moon.(at night?)
7. Burn sage. Start a bonfire of old valentines, old gifts, old letters.
Destroy something that is easy to clean up without hurting others or yourself.
8. Sing and dance your heart out alone in your room.
Your choice of music! or hula hoop naked.