Y has been doing her best to make me into an pro-environment crusader. Before we met, I did things like reduce my consuming footprint and I opted for a small Toyota Corolla rather than a larger, less fuel efficient vehicle (my experiments with fuel efficiency is something that I have written about before here).
Now, Y gently nudges me to do more good for Earth. We recycle and reuse as much as possible. One way that you can put reuse into good practice is by taking your own carry out box to the restaurant with you. Instead of taking a doggie box from the restaurant, it is better to reuse a microwave safe plastic container from home. Doing this cuts down on how many carry out boxes are used and eventually thrown away or recycled. Perhaps overall use of these containers by enough people would cut back on their overuse by restaurants.
A corollary to this is carrying your shopping in hand or using your own bag rather than taking a plastic bag from the retailer. Using fewer plastic retailer bags cuts down on waste and it challenges unwitting advertising on the part of consumers.