Monochromatic designs can be so fun to stitch. All-in-one color or mix it up and use a variegated design for a little fun. This angel and bird mirrored design is pretty in blue as shown here, but would also be fun in pinks or reds or a mix of both.
Ant of Sweden has a nice mix of free charts including this one.
These backpack cross stitch patterns aren’t like the backpacks you would use for school, but they might inspire you to go on a different sort of adventure, and pack your sense of humor.