Don't be afraid to make up your own.
You can develop technique by learning repertoire that's just beyond you. Difficult pieces force us to find little tricks and new methods of practising to overcome technical obstacles. As the technical challenges in a diffcult piece are of a wide variety and are somewhat randomly spread out throughout the piece, you won't get bored. Also, you won't just be training technique, you'll also be developing musicality as you're playing actual repertoire, not just exercises; always bear in mind that technique is simply a gateway to creating the musical images we have in mind.