Not sure where you are but there are many "refill" shops around me where they sell bulk soap, cleaning products, etc. Which I love and have been using for years.

There's similarly places that sell food in bulk and you can just bring a reusable bag/container and get the basics like flour, sugar, seeds, snacks I've even seen like margarine and salad dressings at some places. There's the bulk Barn in Canada and it's pretty affordable

I try to buy only glass or metal Tupperware, avoid using Ziploc bags. They sell reusable sandwich bags now too which are still plastic but much more reusable.

I always have a cup or two with me for coffee and collapsible metal straws. When I used to go to restaurants pretty often, I would bring my own takeout containers.

The basics like bring my own grocery bags and I also have little produce bags to replace the plastic ones from the store, or sometimes I'll just go without a bag for something like onions or oranges.

I still feel like I could be doing much better but it's really hard, especially if I'm buying easy to make food rather than raw ingredients. I do my best to support local places that try harder to provide eco-friendly alternatives, and with the rising costs of groceries, I've honestly found a lot of these places have stayed the same which is still more than the big grocery stores, but not really by that much anymore.