How to write in English for international readers?
I'm not a native English speaker but I've been learning the language for many years in many fields (Mathematics, Physics, Mechanical Engineering and Programming to name some). Every now and then I find something explained in 'basic' English that I just cannot figure out without some search. Along the way I learned some small tricks for writing English for foreigners.
Assume that the reader has an intermediate-high English level to answer this. The reading fluency is the main concern in this question, not the learning of the reader. I also wanted to give my 2 cents in this so I'll answer my own question in community wiki format, so please add your advice there.
This question came up to me after reading the word 'Jeopardy!' in this stack overflow blog post.
EDIT: I read this afterwards (which seems pretty mistaken):
John Saunders: I wonder what proportion of StackExchange users don’t know what “Jeopardy” is?
Jeff Atwood (author): @john I suppose the same proportion that don’t know what “Wikipedia” and “Clicking a Link” is.