I prefer to not mix fabric types or fabric weights in a quilt top or backing -
The reason for that is that I think similar fabrics will wear out at more or less the same rate.
Most batiks are more tightly woven than homespuns, for example.
Most denims will also last longer than flimsy flannels.
For a decorative wall piece, whatever creates the wanted effect -
I'm talking about the quilts made for utility and/or everyday use.