Creating a year long media plan

Customer A has a budget of X amount to run a campaign where the goal is to increase sales for product Y. Based on previous campaign's detailed performance (spend, impressions, clicks, CTR, DPV, DPVR, PR, Sales and RoAS), the ask is how to allocate the budget over placement/packages, which audience should be targeted and what targeting type should be leveraged. Need to identify also opportunities to ask for incremental budget.