One of my students was trying to paint eyelashes on her portrait today with a grass brush. The brush was curved to the right and she needed it curved to the left and the angle changed as well, to match the eyelashes that were already there. I could not seem to figure it out in class but as usual i got it in about 5 seconds sitting in front of my home computer (i think it is because i have my magic photoshop slippers on ?????).
Go to the window menu and down to the brushes palette. Make sure you have the brush tool active in your toolbox. In the brushes palette click on the words
"brush tip shape".
You will then see many options that will change your brush.
I clicked on the "flip x" checkbox to make the brush curve to the left and then played with the angle circle to tweek it a bit more.
Good luck rebekah.