this sounds funny - but i use mozart sonatas. they are easy on you - and yet there are technical difficulties. this way - you won't get carpel tunnels when you work your repertoire as well. save yourself!
unless you want to tackle the brahms paganini variations for fun - but i'd save that to the end of practice session.
warming up, to me, is just enough to get your fingers and dexterity going. not to make you sore. but, once i am warmed up and have practiced repertoire (of which there is never enough time) - then you can warm -down (being already warmed-up) and move from very difficult, to moderate, to easy and then quit. just a little bit from each one. say the first of the brahms paganini variations. i think it has thirds in it.
joseffy has some interesting exercises, too.
and , then there's beethoven's 32 variations on a waltz by diabelli. i like the sound of those and would enjoy practicing them over and over. the brahms handel variations are cool, too.