Spell check is your friend. Have someone else read your resume for mistakes, holes, or disparity. Be specific in what you did—give examples when you can. If your experience is babysitting, say how many kids you watched at once, what activities you did with them, explain that you had kids all day on a weekend… Remember, at your age, everything will count toward showing an employer that you are a capable, reliable person. Include volunteer work, babysitting, lawn mowing, scouting activities (Boy Scouts or Girl Scouts), etc. This will show you know how to be someplace when you need to be, can follow instructions, can complete a project, etc. Be truthful and thorough.