Probably because I was distracted by a little girl tugging on my sleeve and asking for "curtains around her bed"
I remembered, and I've (slowly) been working on it.
First I sketched the cactus on the wall with pencil. Then I painted it in with a celery green wall paint, which was left over from Becki's kitchen, and was a color I originally helped pick out :)
When the first coat of paint was dry, I used craft paint to darken the remainder of the wall paint and sponged it on to give the cactus some texture. Eventually I tinted the wall paint 3 different colors for shading.
After all that, it still looked a little flat to me. I was all out of wall paint by that time, though (the bulk of Becki's leftover paint went to another project - will post that one later!) so I resorted to straight craft paint.
When it was shaded to my satisfaction (3 more days of shading!) I drew the numbers on the wall. I wanted to use an 'old west' type style, so I found one I liked and hauled my laptop into Asher's bedroom with me, so I could reference what the numbers looked like.
I penciled them on the wall first, then outlined them with a sharpie. I painted them in with black craft paint.
I do wish I'd had more shades of real wall paint to use, rather than so much craft paint, but overall the cactus turned out really cute - both Asher and Tessa love to stand next to it to see how tall they are.