I love transitions to work on getting your horse to move off your leg and respond lightly to your reins to come back down. Work on straight lines off the rail (harder than you think), circles, figure of eights, and serpentines - all things that will work on manuverability. Start big, go small, and back and forth.
To get her to work on contact, side reins are great lunging if you know how to use them properly. Also try using light contact, and driving her into the bit with your legs - try to not punish her with your reins when she tosses her head, instead push her up with your legs. Then work at different rein lengths; go on contact for a few strides, then giver her her head as a reward for tolerating it. Keep going back and forth until she knows that even if you have contact, there will be a break. Also work sometimes with light contact, sometimes stronger contact; but remember that the more contact you have the more leg you need.
I have a few other ideas, but have to get to work so I'll try to post them later.