Once you choose the pony that you like, buy new things to decorate him as you like. Select them with the left button of the mouse... Return home to select the things that you have bought.
Dress up and make up this girl in the way that you like, and you can customize the colour of eyes, hair, clothes and accessories... Use the mouse to make selections.
Select the clothes, accessories and colour of hair that you more like, leaving the protagonist with the appearance that you want... Do the selections with the mouse.