When you created a macramé plant hanger, you will probably have to cut the strands at the end. The good news is that you can still use these leftovers for creating key rings!
For each of the above examples, I only used 4 strands of ~35 cm macramé yarn of 4 mm thickness that were indeed the leftovers. In addition what you may like to use are beads with wide openings, scraps of thin colourful cotton yarn and a ring.
In my local craft store I found beads that were of untreated bare wood. These are great since you can easily paint and decorate them yourself. I used a thin knitting needle and placed that on a couple of tetrapacks (aka milk cartons) so it layed steadily. I used acrylic paint with a coat of matte varnish which dries quickly.
For the above examples I used 4 macramé strands and I placed the ring in the middle so that I ended up with 8 strands of macramé to work with. I only used the square knot and the spiral knot. There are many tutorials out there and I found this one a very clear way of explaining these basic knots: 3 basic macramé knots.
The start of a couple of these key chains was made by wrapping the thin cotton yarn on it very firmly. You can let the start of the thread be wrapped within it. When finished, with an embroidery needle you can insert the end of the thread back in the winded part and cut it off so you will not be able to see it.
With the type of macramé yarn I used, you can create nice looking fluffy ends since the strains consist of multiple strands that you can unravel.
The 4 keychains in the picture I created just in a couple of hours – nice activity to do with kids or friends on a rainy afternoon.