Sleep training help for older baby

Florence
Can anyone share with me how you trained your baby to fall asleep in the crib on her/his own? I have a 6 month old and am now starting to sleep train her. She outgrew her zipadeezip, so now nights have been an exhausting dance between her waking up every two hours and crying because I won't hold her while she is sleeping. 
I know teething is a possibility, but I'd like to know what you did that worked.