I heard from R’ Shlomo Gottesman that there are many segulos for parnassah which some people subscribe to and some do not, but here are three segulos that are guaranteed to work:
- Give tzedukah (maaser);
- Say Birkat Hamazon properly each day; and
- Say Bareich Alainu in Shemona Esrei with proper kavanah.
Emuna Daily 
Just want to add that Davaning to Hasham is the biggest Segulah.