If a crime or suspicious activity is involved, give the time and date of the occurance, decribe the suspect(s) and vehicle(s).
Give as much detail as you can about people: age, height, weight, sex, race, hair color & style, glasses, clothing, shoes, hat, facial hair, tattoos or scars, gait or limp, etc. For vehicles: license number, make, year, color, body style (2-door, van, etc), identifing dents or scratches.