Leave the cuttings somewhere with overhead protection from direct sun while they are rooting. Do not water right away after you have potted them up. Wait a week or two first. From there on out water carefully, so that the soil goes dry at depth in between each time. Remember that the cuttings will not be able to use the water until they have roots to take it up, so do not overwater while they are rootless. Once they are properly rooted they will change on top, looking more plump and putting out more new growth. That's your signal to gradually begin ramping up the exposure.
Not that it matters for the purposes of propagation, but the plant is some other Euphorbia, not trigona. I couldn't really say which, though.