I also had a problem with my elbow this february probably because it was so cold and I played 36+ holes three days in a row. SO being relatively new to the sport I went to the doctor right away so I didn't slowly injure myself over time and in a few years then I would not be able to throw any more....
Anyway, i just tried to explain it but after having written 5 lines I though "who the heck is supposed to understand this"
So I will just leave it to other websites to explain the way I stretch at the moment, and I just have to say it helped a lot. I do it twice a day plus everytime before (and after if it was longer than about 2 hours) I played...I think stretching is even more helpful than strenthening...but just my opinion, not the one of a medical http://www.livestrong.com/article/480441-anterior-capsule-shoulder-stretches/
Just the way that guy on the picture does it, 25-30 secs for stretching the tendons and 15-20 for loosening up before/after disc golf is what I do
ps: I know it's a shoulder stretch, but it takes a lot lot lot of force of your smaller muscled elbow, at least that's what my doctor said..