Potential sample is a group of international students, therefore, I wish to find a method not involving solution of sophisticated grammatical puzzles .
If you know such measure I would be very grateful for your sharing!
There are visual creativity tests such as the creative mental synthesis task (Finke & Slayton, 1988) or the Torrance tests, some of them are non-verbal. http://en.wikipedia.org/wiki/Torrance_Tests_of_Creative_Thinking
Perhaps the best measure of creativity, in the form of a questionnaire, with excellent psychometric qualities (i.e., reliability, validity, absolute zero, etc.) is the Creative Achievement Questionnaire. I believe Shelly Carson is the author, and we have published neuroimaging correlates on it: http://www.ncbi.nlm.nih.gov/pubmed/19722171
I need to check on those neuroimaging correlates! Have you seen Weisberg's lit review of that topic, in the Creativity Research Journal? I am just finishing one that focuses on divergent thinking.
But as to the question, it may be that divergent thinking is best--it does work well across cultures. The rCAB (creativitytestingservices.com) has DT tests with reliability data from 7-8 countries now. But that is for creative potential, which is different from what you would get from the CAQ. Our "Many Uses" game works especially well across cultures.