Getting a 6 month old to fall asleep

I have a 6 month old and we have the hardest time getting her to fall asleep unless we are holding her. It sometimes takes 2 hours of her crying (in our arms!) before she falls asleep. We do a full bedtime routine, She has a clean diaper, a full tummy, no reflux... I didnt believe in the cry it out method when she was younger and I don't think she's old enough for that yet. I hear other moms saying just to put her down but I can't just let her scream... Any advice?