A "spike" is an area where you develop exceptional depth - something that makes you stand out. Freshman year is perfect for exploring what yours might be!
Instead of being "well-rounded" at everything, colleges increasingly value students who are exceptional in one area. Examples:
Focus on final exams
Freshman Year
Document summer accomplishments
Junior Year
Set up organizational system
Freshman Year
Start activity tracking document
Freshman Year
Begin college conversations
Freshman Year