2 Answers

Business trip or pleasure? 
Business:
Straight-forward and to the point.
"In Madrid, I met with Senor Macias, vice president of blah blah blah.  We discussed the new blah blah blah.  Sr. Macias agreed that the marketing strategy (yada yada) was well thought out and could be easily implemented. He suggested billboards along with the television spots and offered an additional budget of 4.6 million, earmarking the funds for bi-lingual advertisement."
 

It would really depend on the reason you were sent there, address the issues, discussion, proposals and any conclusions or agreements reached, your question is a little lacking in detail,so make your report accurate and to the point