Bottom up cardigan

Hi can anyone help me I’m knitting a bottom up cardigan and I want modifie it by knitting the top half seamless I know how to join all the parts but not sure about the decreases any help appreciated

Do you want to join the sleeves to the body and knit a yoke on the cardigan? The best thing is to look for a yoked cardigan on Ravelry ideally in your gauge. Follow the decreases recommended there.
Another possibility is to look for one of Ann Budd’s books which gives templates for several sweater types in multiple gauges.

Hi thanks for your help I’ll have a look on raverly