Here's a short list of ways to spice up your single note lines, lead breaks, solos, or whatever. This is guitar stuff, but may be transferable to other instruments.
hammer-ons, pull-offs, slides, slurs, bends, tremolo, vibrato, whammy (ever try a Peavey acoustic with a whammy?), harmonics, behind the nut or tailpiece bends, chords including double-stops, power chords ("5" chords), octaves, fingerpicking, volume and tone swells, bottleneck, detuning on the fly, staccato, legato, pauses, interval leaps, chromatic runs and accidental notes, arpeggios, muting, percussive scratching, pick scratchs, etc...
Even the most banal lead break could be improved with subtle use of some of these tools. One caution, don't sacrifice the note(s) to weird techniques. Sometimes it's better to spend your thought on choice of notes/harmony than on tricks. Other times tricks are what works.
More later. Mooh.