I am a big fan of the clam licking
Some thoughts:
Don't just head straight for the 'pearl', in keeping with Jasser's theme. Run your tongue along the inside, between the inner and outer lips...there are a ton of nerve endings there. Take your time with the clam. Circle all around it, everywhere BUT the clit, occasionally running your tongue across it only momentarily. Do it just long enough to make her crave more, before returning to gentle licking and sucking of the other clam parts, and there are many! Keep teasing the clit, brushing against it from time to time but no all-out licking just yet. When she is finally begging you to give her clit your full attention, start off slowly and gradually increase the intensity/speed/pressure. Gently slide two fingers inside her while you are doing this, and make a 'come hither' motion with your fingers inside her, massaging her g-spot while you suck on her 'pearl'. No need to ram it in and out, that's shit they do for the movies. Just keep them in there, and give the sweet spot a nice rubbing.
..Just a few pointers that came to mind