4. Keep away from jargon
Your job as a course developer is to engage learners and encourage them to complete the course. This is only possible when you use words that are easy to understand, in a conversational and friendly tone. More importantly, avoid "business speak" or a tone that sounds trite, pretentious and confusing. Also, check your tone of voice, if it sounds forced, revise it and make sure the sentences flow naturally.
5. Think in terms of usefulness
Your material is limited. It has to be. You can't include everything you find amusing in it. that's why every paragraph or element in your course should serve a purpose. Funny videos and catchy images are great but if they don't provide actionable information, then they don't deserve the attention of busy learners.
Make your learners DO things. Focus on what the learner needs to be able to do at the end of the day. Have the learners do something with the information. for example, give them something they can use, like problem-solving content.