Sleep training on own


Does anyone have any tips? My DD (dear daughter) who is almost 4 months, hasn’t slept on her own, like I mean she only sleeps if she is on me..i need her to take naps in her own bed and I plan to really try tomorrow since my DS (dear son) is starting school and it’ll be quieter and calmer in the house. I just don’t know where to start, she does take a pacifier and we just got her switched onto the bottle. I’ve tried laying her down before by herself once i got her to sleep and she wakes up and just screams the entire time and won’t calm down until I pick her up and get her back to sleep. Do i just need to keep repeating that and maybe one time she’ll just stay asleep for naps..i never struggled with this with my other two babies.. Any help is apperciated!