Simplicity is a way of life. Live a life of happiness by helping others and creating a space and wardrobe that are both personal and easy.
A cluttered space causes stress. I encourage you to organize your space, get rid of things that lack importance. The projects and journals from high school don't serve a purpose later in life. The way you look back on the past could negatively effect your self image. Focus on the present, and create your space to keep you thinking about the present, not the past.
Create a wardrobe that makes it easy to choose coordinated, appropriate attire for every occasion. Have well fitted basic pieces that are of good quality and never need to be replaced. Organize your closet so you always know exactly what pieces you have. Dressing will never be easier.
Live a healthy life. Clean eating isn't just about having a healthy body, but having a healthy mind. A clear mind allows positive thought. Stock your kitchen with fresh vegetables and eat them. Freeze berries for easy smoothies. Stop eating processed grains. Drink green tea.
Never stress out about what you don't have. If you need new running shoes, buy them. If you were the last person on earth, money wouldn't matter, but quality shoes would.
Get a puppy. Nothing is more rewarding than raising an animal who loves you unconditionally. And they make great running buddies.