How to become more customer friendly in retail?

Okay let me explain first I work in a bakery at my local grocery store. I've been there for four years but I've been at the same store for 12 years I used to be a cashier anyways obviously being in retail for a long time you know it starts to drive you crazy and I noticed I haven't been as customer friendly as I used to be now I'm not saying I'm rude to customers it's just I seem less active and less talkative to them than I usually am. I want to stop being more customer friendly again any tips how to he more customer friendly. Like I said before I'm not rude to them I will never be you to a customer it's just I feel like my customer service skills if you want to call it haven't been the way I wanted to be.