My little boy struggled with reflux and colic, so we had a LOT of crying in the early days. For him, as now, it was all about comfort and close cuddles with Mummy. We tried white noise apps but they didn't seem to cut it. There were also some Happiest Bsby on the Block Youtube videos demoing holds that we tried, but mixed success with those.
What worked for him was being kept as upright as possible when holding him, and walking. We must have walked miles back and forward in our bedroom , and walking at speed worked best. Shshshhhing him helped too. He like me singing to him too, especially Mama's Going to Buy You a Mockingbird, and other songs tweaked to make the lyrics fit. For some reason, the Downton Abbey theme tune always stopped him crying, as did The Phantom of the Opera!!! We had a nursing chair in his room when he got bigger, and gentle rocking snuggled up to me in that soothed him too.
Infacol was also a Godsend!