The image above shows licking up and down directly on the clit and the image below shows licking the clit from side to side.
Use your thumb to pull up the hood so you have more direct contact with the exposed clitoris. Pro tip: this increases sensitivity, so you will need to recalibrate pressure, depending on how sensitive her clitoris is.
“You can continue giving your partner big, long licks with your whole tongue, sliding your tongue from the vaginal opening all the way up over the top of the clit, and back down. Keep continuous pressure and contact, like a violin bow sliding back and forth across the strings. The more surface area you create with your tongue, the more friction you can give your partner across a wider area of her vulva. To give more precise sensation, use the tip of your tongue. Just like you would with your fingertip, you can use the tip of your tongue to flick across the clit head using side-to-side or up-and-down strokes, depending on what direction your partner likes best. With constant pressure, you can also trace circles with the tip of your tongue, sliding around the clit head and across the hood.” – Excerpt from Beyond Satisfied by Kenneth Play, Chapter 11: Oral sex, How to Give a Good Licking