Although I'd like to get better at this still, I've made some changes over the past year or two to decrease how much waste I create. Mostly this means finding reusable alternatives to disposable items I use often, and avoiding unrecyclable plastic when I can.
In case they inspire you to make a change too, here are some of the things I've changed so far.
I don't use straws too often, but often enough that I had a packet of plastic, disposable straws in the pantry. I replaced those with metal straws that I can wash, and which are quite nice to use once you get used to them.
Reusable shopping bags
Probably the most obvious and recognisable idea on this list is to "take your canvas bags to the supermarket". I picked up this habit from Josh before our supermarkets banned plastic and these days we always either take a bag or just carry things in our hands/pockets.
Washable produce bags
Extending the canvas bags idea, I hate having to waste so many plastic bags every time we go grocery shopping just to buy fruit and veggies. Although our supermarket offers degradable produce bags, they're still disposable plastic that's easy to avoid. I bought a set of washable produce bags that are light to carry and can go in the washing machine.
Pre-empting avoidable plastic
I'm not much of a bag person. I prefer to carry all I need in my pockets, unless I'm going to the gym or on a trip where my big backpack makes sense. So I've been trying to think ahead when leaving the house to pre-empt cases where I might end up with disposable plastic. For example, throwing a plastic bag from home in my pocket when I know I'm heading out to buy something too big for my pockets.
I use napkins at meals a lot, and I used to just use paper towel. These days we have a nice set of rainbow cloth napkins that are nicer to use and less wasteful.
Saving boxes for moving house
I've bought new or used boxes the last few times I moved house, but since the last move I've been more careful to examine every box we get something delivered in to see if it's a good shape and size for packing. We often find we have too many tall boxes that end up full and heavy, and not enough short, easy to carry boxes, so we've been especially mindful of keeping different shapes and sizes. Since we tend to move house every couple of years, this is particularly pertinent for us.
Saving wrapping paper, string, etc. to reuse
Saving present wrapping to reuse always seemed a bit extreme to me, but I've found it really handy recently to have a few different present bags and ribbons on hand in different sizes, saved from presents we've been given. It's nice to not waste those wrapping objects, and to save money we'd otherwise spend on brand new stuff.
I use a lot of cling wrap, and it always strikes me as being wasteful. Beeswax wraps can replace some uses for cling wrap (you can't put them in the microwave), and they're washable. So far I've found they're really handy for wrapping up leftover chunks of vegetables, like half an avocado or sweet potato.
Menstrual cup and period underwear
Not only do these reusable options save on the waste we create when menstruating, I also find them way more convenient and more comfortable in some ways. I'm happy to be leaving pads and tampons behind. Oh, and I also chose a cup that can be recycled at the end of its life, which is extra handy (mine is the Hello cup).
I never imagined I'd take up composting, since I'm not really into gardening, but I found a method that's really low effort. It's called "dig and drop" composting, and the idea is that you take your food scraps (vegetable peel, apple cores, coffee grounds, etc.) and bury them in a deep hole in the ground. We have some empty garden beds in our backyard that work well for this, and we've seen the soil look much healthier since we started. We're also filling up our rubbish bin less often by composting our fresh food scraps.
P.S. I make some stuff you might like: Exist, a personal analytics app to help you understand your life, Larder, a bookmarking app for developers, and Changemap, a roadmap and changelog for transparent teams.