Do you have sensitive skin? The best way to know is to ask your local dermatologist. Symptoms determining a diagnosis of sensitive skin can include skin reactions like bumps, pustules or skin erosion, excessively dry skin that may not properly protect nerve endings (which can cause reactions to skin products), and a tendency to blushing of skin flushing.
Sensitive skin is caused by a myriad of reasons: skin disorders, allergic reactions linked ot immune system dysfunction (eczema, hives, rosacea), excessive exposure to skin damaging environmental factors, etc.
So what should you look for products when caring for your sensitive skin? Unfortunately, there are no specifics, but there are some skin-friendly tips. Find products with few ingredients that have little to no fragrance; avoid products containing alcohol, antibacterial or deodorant ingredients, and retinoids or alpha-hydroxy acids.
As for makeup here are some suggestions from the American Academy of Dermatology. Use silicone-based foundation, face powder, and look for cosmetics with fewer than 10 ingredients. Pencil eyeliner and eyebrow fillers are best, since liquid versions may contain latex, and earth toned eyeshadows, which are less irritating than darker colors.
Go here for some more info on caring for sensitive skin: WebMD