I worked at Spirit Halloween for 3 years. Here are 9 mistakes I saw customers make when shopping for costumes and decor.

Although I worked at Spirit Halloween — the seasonal chain known for taking over empty storefronts — for three years, I've been a longtime customer and have even joked that the store was created just for me.

Here are nine mistakes I saw customers make while shopping for their costumes and seasonal decor at the popular Halloween chain.

Only coming into the store once per season

One of the biggest mistakes I saw customers make was only visiting once per year. The stores get truckloads of new merchandise delivered weekly, so chances are you'll find something new every time you stop by.

I also…