You can easily affect what the customer purchases but firstly you must create the correct environment. Customers are busy people and if they cant find what they are looking for you will lose them. There are many choices to be made based on your market demographic.
On line, omni channel what route to market, what products.
Store layout, what does it say and what about theft.
Reducing the cost to operate by tactical store layouts.
Using the 80/20 rule, must have stock.
Why 'click & Collect.
What products where.
Sourcing based on analysis.
Delivery planning to reduce costs.
Team member contracts.