Always carry a Tot bag with you, or bring your own shopping bags to avoid buying more plastic. 

Make sure to use reusable items: reusable water bottles instead of plastic ones , glass jars,  candle pots, and you can also turn paper and magazines into creative collages

If you don't use / wear something anymore sell it online: On Vinted, Amazon, via instagram etc..

Be creative and re-use coconut shells into plant pots, an old tee-shirt into a sport-bra, wine bottles into flower vases etc..

There are a lot of DIYs on the tube!

Don't waste your food, bake a banana bread with your ripe bananas, make apple sauce with your ripe apples, jams with your extra berries, use your ripe avocados in smoothies, carrot peels, shrimp shells into fish/ seafood or veggie stocks. 

Ban all the plastic straws, plastic bottles, plastic cutlery and make sure to always buy seasonal products (if not organic)

Reduce or cut down your red meat intake and try new plantbased options (tofu, tempeh...), invest in an apartment-friendly or traditionnal compost, grow your plants and herbs at home and why not get a few chickens in your backyard for safer eggs and delicious omlets?