Best modeling technique to follow?

[chemicalab]

Hi all,

Lets say that i would like to model the sales of a company against various campaigns that they have like TV, Radio etc, competitors, Halo effects in order to obtain ROIs and contributions.

Within the procedure is also to give adstocks and curve transformations for every variable in order to model them against the sales.

What would be the best method to follow in order to obtain such a model?

Thnx in advance and let me know if further clarifications are needed.