My favorite version of "decorating" is to take any plain jane object and. . . . .
add some pattern to it. Wham-O! Instant visual gratification.
This is a super easy project but for those of you who like a bit of guidance when it comes to crafts, (I do too) here is a mini tutorial. I took some leftover wrapping paper, pressed it into the nook, then traced the outline of the inside. I imagine that newspaper would work just fine too but it always make me sneeze. I used the pattern to trace the shape on to this lovely paper. (Purchased on clearance woot-woot.) I cut out the shape and attached it to the wall with double sided tape. The single detail that needs special care is to be certain that you trace your pattern onto the correct side of the paper. This arch may look symmetrical but if you try to hang paper on the right side that has been traced with the left side of the pattern you will quickly see how unique each curve is.