Grow my dropshipping store

I own a shopify store called jellajelly.com I'm trying to have more of a longterm work. With a road map and plan that can be processed through. I know that sales can never be certain but based on your past experience working with clients shopify store. What might have been the duration of time in which a consistent flow of sales resulted from specific marketing tactics? Also, can we replicate a similar step by step process so that I know how much money I am spending and how much I can expect back within a certain duration of time?