To be finicky or excessively critical; to potter; esp., to work with excessive care for trifling details, as in painting.
To use, spend, or do in a petty or trifling manner.
To elaborate excessively, as in art.
worry unnecessarily or excessively; "don't fuss too much over the grandchildren--they are quite big now"
argue over petty things; "Let's not quibble over pennies"