Yes, I grow the locally native species of milkweed (some for my garden, but increasingly to give away to neighbors interested in starting to garden more responsibly). I start my milkweed seeds in repurposed mushroom and berry boxes. With the former, I cut small slits at all 4 corners to provide for drainage.
Permanent markers (for making plant labels) can be stored in a plastic tub in which our cats’ treats are packaged. Plant labels are cut up horizontal blinds rescued from a neighbor’s curb on bulk trash day.
We store our cat’s insulin pens in the refrigerator in a small glass bottle which contained some food item.
I love to read the ideas of other’s (and/or their actions), as that promotes the reuse thinking you describe.