A grid composition can be very gratifying.
The mixed-media painting shown below is extremely textural.
I added sawdust to the paint, but you can try crushed eggshells, sand,
or store-bought texture mediums.
Pastel tones may not be your preference, but for a large,
soothing work suitable for a bedroom, perhaps,
colors with white worked out ok for me.
Here's another idea if you feel your grid is too boring: Add lines,
scribbles, or stamped-on words, numbers, or letters.