It would be much easier to root a spider plant (Chlorophytum comosum) plantlet in soil. Leave it attached to the mother plant until it has rooted and shows strong healthy new growth. Then sever the stem connection the two.

Sorry I have no advice on the coleus cuttings. I start new plants from seeds.

Good luck!

syrinth, I have had success by filling the cells of a grass plugs tray with wet perlite (dry perlite has a mind of its own) and sticking a cutting in each cell. I water the tray gently from time to time to maintain a damp condition. When the cuttings are rooted, they can be easily lifted an placed in a hole prepared in the middle of a 4" pot of good indoor potting soil. The perlite that adheres to the transplant helps to keep the root zone of the new plant from becoming water soaked.

cool, my next plan was to try that except with Turface :D

Will the fact that some of them are just sticks now cause a problem?

Its alright Syrinth, you don't have to explain why its the shot glasses that are being used...we believe you.....LOL..

generally its thought better to remove all the leaves except the top two. Too much pressure on the plantlet to keep moisturizing and feeding the plant makes it much easier if we remove excess leaves.

If you go the soil root, perlite/sand/peat moss/vermiculite and potting soil/potting mixes, you can give thought to using a rooting hormone.
A few drops in the first watering, or poke a pencil in the medium and place the stem into the hormone and blow off the excess is only thought of as a consideration, not cemented in.
The plain water or medium without hormone is very common.