Scrumble Scarf: The crazy quilt for yarn

The point of freeform knit/crochet is that you don't have to follow a pattern. Just follow your fancy. My fancy is a very lazy beastie. I've just finished a simple brown & teal garterstitch scarf. The last foot has increasingly large holes as a framework to attach the scrumbles. While I like the randomness of adding various scrumble shapes haphazardously, sewing them only to each other seemed like it would strain the more delicate shapes. Also, my inclination is to choose floral and organic shapes. The scarf is the trellis on which they will creep.
When I made a crazy quilt doll blanket, I sewed the bits onto a base of muslin for stability. This is the source of my notion. Not everyone does...but it makes me feel safer.
Color-wise I'm not yet sure which way I'll go. I read somewhere that if you use less than 10 colors, take care that they go well together. But if you use more than 20 colors, it will be an agreeable riot.