We sit her up, hold her head up just under the chin and rub and pat her back. We also rock her back and forth in that position.
This is what we do, too. I like it because I can see his face and I know if he spits up. I have also had to bicycle his legs a little to get him to burp.
You might look at your own diet to see if there's something you're eating making your LO extra gassy. I cut down on dairy (didn't completely cut it out) and LO seems to be less fussy after feeding.
Also, I learned and a Mom + Me group that I was feeding LO too fast. Slowing down his feeds and letting him take a good break between sides seemed to help a lot.