No science behind this but if I find myself in potential lightning strike conditions, I tend to go low. As far as I am aware, virtually all the North Sea lightning strikes have been in the 2000' -3000' altitude band (because these are the most common flight altitudes over the NS).
In a previous life, also on the NS, after we had had a couple of strikes within a few days, our technical director contacted NASA as they have some of the best knowledge about lightning strikes. In those days, the space shuttle probably would not survive a lightning strike so NASA did a lot of research on this subject.
One of their experts came over from Florida and gave us a presentation on the subject. One thing I do remember from the presentation was that he confirmed that the 2000'-8000' band was the highest risk altitude band for aircraft lightning strikes.
I do get some raised eyebrows from some of my younger copilots when I say "lets go down to 500 feet until we are clear of this" as low level flight is virtually unheard of nowadays on the North Sea.