My warm up routine has become a little dull, and I'm looking for suggestions.

[rudjarl]

You can never really skip practising long notes and scale, but nevertheless, it can easily become boring. To spice things up I sometimes skip scales and long notes in favour of playing reasonably simple tunes that have long phrases and some chromatic motion. Tunes like 'Why Can't You behave?' by Cole Porter have phrases so long you'll need an oxygen mask at the end of it, and chromatic fingering enough to prevent you from noticing you're running out of air