My daughter had a hard time burping too, when she was an infant.
1. The normal, put the babies top chest on your shoulder being careful of her head, and gently rub and pat on her back.
2. Hold your babies chest in your hand, sit the baby up on your leg with her leaning towards the hand you have on her chest. Use your other hand to rub and pat her back.
3. Walk around holding the baby upright, not laying. While you are walking, rub and pat.
All babies are different, and once you find the best way to get YOUR little one to burp, that's the way to stick with.
Good luck to you, and believe me, this time passes by far too quickly...even when the baby is fussy, treasure this time...