Lunge her until she is dropping her head or at least blowing in both directions, and when riding do lots of transition work, stretching, serpentines, something to keep her thinking and hopefully that will get her to relax. For hot horses I find you really want a good warm up routine before you start working. Good luck, I hope you find some of this useful!
There’s this horse that I’m supposed to start training. She’s been out of work for the past 6 months due to being lame and she’s now allowed to be worked again. She was already quite hot before so no doubt she’ll be worse after not being ridden for some time. I’ve been told to lunge her before I ride which I will do but any other tips?