If he/she has gotten his I-20 under no curcumstance he/she should wait and see for the perfect time........he/she should apply for F1 visa immediately. If the visa officer rejects in the first instance he/she should not even give a f** about it and give a F*** to the visa officer, delay the enrollment until succeeding semester, get a revised I-20 and apply for the visa after 3 months once again. This time it will be a breeze. That's axactly how I got student visa, travelled to the US, went to school in Michigan. Moved to Canada and settled here in Canada.