If you're pressed for time, or just don't feel a large gravestone is the best thing for you, you can always try something smaller.

You need:
• White paper or construction paper
• Markers (if during the rainy season, I recommend permanent markers)
• Masking tape
• An epitaph

Optional:
• Scissors

OR
• Post-its and a marker.

What to do:

-Write your epitaph with a marker on whatever you are using.
-If you have time, you can cut it in the shape of a gravestone and write R.I.P on top.

Take it to the place the tree once stood and tape it there. Good job, you are finished.

PS - Hey, and if you'd be so kind, might you not write "Gravestones For Trees Campaign" on the back? Spread the word!