Some considerations when producing trigger material

should grab the learners' attention. There are likely to be a range of interests in the group, so how are you going to grab them all? (or at least most of them)
should be at a level with, and relate to, learners' current level of experience, knowledge and understanding
should be designed to stimulate questions through appropriate cues, so that learners can identify areas for study relevant to the desired learning outcomes
should not usually provide answers within the material or be solvable at first glance, or with the information given - the whole idea is that students go off to research them. You may wish to provide them with references and/or material to help this, however
should be authentic/real/believable (although not necessarily a real clinical case)
will model values, orientation, context (the 'hidden curriculum"): So check that - the framework, language and tone of the material reflect what you want to model
should be given in smallish chunks - consider staged release of material if there is a lot (but note that long, complicated trigger material may reflect teacher anxiety!)
should be 'to the point', since learners need clues about what is expected; extraneous material may be unhelpful and distracting
hopefully shouldn't take too much time to produce and ideally should be re-usable
should be cleared for confidentiality/consent sought if based on real cases