Teaching tough subjects or lessons can be quite challenging. However tough subjects can dealt with in systematic steps. Enumerated below are two steps that when practiced well can simplify the toughest of subjects for your students.
Peg down the problematic areas and attack them well
Pen down your teaching plan and identify those aspects of the lesson that you feel would be tough for the students. Spend specific time to identify what teaching aid can help ease the toughness. A teaching aid can be something like model, an experimental apparatus, a chart, a video, etc. If a teaching aid does not help, try to see if you can plan an activity or an experiment around the tough aspect identified.
For example, teaching trigonometry can be tough. The specific parts that students find tough is the real life utility of trigonometry. A math teacher should hence focus on practical life examples where trigonometry comes to the aid before getting down to text book theory.
Enforce repetitive learning
Most times the toughness of a subject is due to the fact that students do not revise the stuff taught to them within 24 hours. It is well documented that the human brain tends to forget 90% of newly learnt things within 24 hours. A revisit of the topic within this golden period of 24 hours helps retain it for a longer period. Subsequent repetitions reinforce the stuff in the mind.
Teaching tough subjects must therefore also involve forced repetition and bite sized chunks of information.
Let me know what methods have worked for you.