PowerPoint
You can use a standard design theme for it. You can be very consistent in how you lay out each slide. You can make sure there are no errors in things like spelling or general content. You can have a good structure. You can make sure you don't have too much content on a slide. Don't have too many slides. Don't use too many fancy things, and don't use fancy things purely to try to make it look better. Often that can make it look tacky or worse. The focus should be on what the content is and what the presentation is about, rather than showing off what you know about
PowerPoint by doing things like fancy animations. Just use them where they are needed and use the standard ones, and only use the more fancy ones if they are particularly appropriate to the point you are making.
