Alright, you have ALL heard me say or seen my type, I am 5'3" if I lie a little bit. Depending upon where I am in the country I feel normal or kind of short. I looked it up and the average American (non hispanic White woman) is 5'4" according to wikipedia (not that I love using them for a source but it's ok for this) so that doesn't make me that short really. But sometimes I feel super super short depending upon who I am with.
Now, owning your shortness is perfectly fine but if you like to feel a little taller like myself, following things to consider to appear taller, which of course then can make you appear slimmer as well... something none of us generally mind. ;)
1. Wear a little bit of a heel: No, no, no, you don't have to wear incredibly tall ones but heel can literally make you 1/2 inch - 3 inches taller sometimes super comfortably if you get well build shoes. Also look for lines that have extra build in cushion in the ball of the foot which will also make them more comfortable.
2. Make you legs look longer: If you are shorter or wanting to appear more lean, focusing on make your legs appear long is a great place to start. Wear hight rise jeans and even do a "half tuck" of your shirt if possible to make that leg line as long as possible.
3. Belt it: If you are wearing something boxier that you feel makes you look "refrigerator wide" belt it and then finagle the fabric upwards a bit and "blouse" it over the top of the belt. This will make your leg line appear longer AND give you a defined wait. See pictures below ;) 
4. Create "visual length" by using a v-neck, or even leaving a button down shirt unbuttoned a bit to create V neck
5. Wear a slightly pointy toed shoe. It doesn't have to be super dramatic. But a square toed shoe stops the "visual line" abruptly where a slight point allows the line to continue on.