Summarize the following:
If you don't mind the flare style, look for jeans with a flare around the leg rather than straight-leg varieties. This draws attention to your bottom half, making your legs look longer. Make sure that the flare jeans do not drag on the floor as this can make you look shorter rather than taller. If you like to wear dresses, consider dresses that cinch at the waist just above the hips. This makes your body look well-proportioned, lengthening your frame overall. Avoid dresses that are long and loose as this can make you look like you're drowning in them, drawing attention to your height. For example, go for a dress with a pencil line skirt that cinches at the waist. Take a pass on the baggy maxi dress. A higher waist helps make your legs look longer, stretching out your figure overall. When selecting pants or skirts, look for ones that are meant to be buttoned and zipped at the waist. Bottoms that fall at the hips are much less likely to lengthen your frame. If you are having trouble finding high-waisted garments, look for vintage styles. Many of them tend to have higher waists. If you find your pants sag near the crotch, either have them tailored or find another pair. Saggy pants in general are unfashionable and can be especially un-flattering if you're on the shorter side.  If your pants look like they're sagging, this will make you look shorter overall. If you can't get new pants, pull them up so that they don't sag, and wear a belt to keep them up. This is a must if you're trying to look tall, as saggy legs draw attention to your shorter frame. If you really struggle to find a pair, you can always have a pair tailored or cuff the legs yourself.

Summary:
Opt for flared jeans. Go for high-wasted, form-fitting dresses. Pick high-waisted pants or skirts. Make sure the crotch doesn't drop. Keep the legs of pants at your ankles.