In reply to bouldery bits:
I used to get periodic episodes of it in both elbows (golfers/medial epi), but strangely seems to have troubled me less over last few years, despite doing more bouldering (which I thought would make me more prone to it).
In the past I had some success with internal/external rotation using a TheraBand, and also eccentrics using hammer or dumbell with weight on one end. Plus a bit of self massage.
I have generally done less finger boarding and I tend to spend longer warming over last couple of years (but more bouldering??), both of which might have helped with it not reoccurring. I'm thinking of diving back into a block of more structured training and finger boarding over the winter so will be interesting to see what happens.
Push ups seem to really help also, I think doing them on a regular basis has help balance out my push and pull strength, and generally helped with antagonistics.
Dave Macleod Make or Break book is good for detailed info.