For many women, the 20s are a time of constant change and personal discovery. Many life-changing events take place during this time, including college graduation, career decisions, romance and marriage, starting a family and discovering interests, passions and hobbies. Birthday gifts during this time should reflect the growth and change in a woman's life.

When she's 20 to 21 years old, a young woman is usually attending college, seeking internships and figuring out personal style. Give her a blank journal, encouraging her to record important memories, or try a digital camera if she doesn't have one. Consider giving her a tasteful piece of jewelry that will match business casual outfits. In honor of her 21st birthday, buy a set of champagne flutes or wine glasses, building up her kitchenware collection.

Between 22 and 24 years old, most women are still transitioning into young adult lifestyles. For a young woman living away from home, try decor for her dorm room or apartment, including posters, area rugs, framed art and organizers. If she's planning to study abroad, give her a sturdy and stylish luggage set. For a beauty-conscious young woman, try a luxurious shampoo, lotion or mineral makeup that she might not be able to afford.

Mid-20s women are getting more serious about the future but still having fun. On 25th to 27th birthdays, try gifts that combine practicality with entertainment. If you know her favorite perfume, look for lotions and bath items in a matching scent. Try a full collection of kitchenware, including cookbooks, pots and pans, utensils and potholders. A subscription to a magazine or a DVD service such as Netflix will keep her entertained for a long time.

When celebrating 28th and 29th birthdays, women are usually advancing in their careers and thinking about starting families. Monetary gifts are suitable for young women making major financial decisions. Give the gift of a savings bond (which will continue giving for years to come). Since she's probably busy with outside obligations, try a gift that relates to her personal hobbies (such as painting, gardening or hiking), or a spa getaway for some relaxing time alone.