When I did my article for Flyer, I sent in a very short precis and some sample photos (photos are very important I think). They wanted to see more pics. I sent them, and then they said write it up. Suggest you do this, rather than write up and get disappointed.
They gave me an indication of the number of words they were looking for, but left the rest up to me. 99% of what I wrote remained in the final article, so I was very pleased.
Didn't ask for or get any reimbursement
, would have thought it was worth a year's free subscription or something, but there you go. Some have hinted on these forums that it might be worth asking....