The first step to developing and delivering more effective powerpoint presentations is to understand exactly what you are trying to achieve with your presentation. There may be several stakeholders you have to satisfy with your presentation ranging from your boss, yourself, and your client. Each stakeholder will expect something specific to be achieved by you delivering a presentation. You need to identify the expectations and understand how (or if) you can meet them.
If you can’t achieve it in a single presentation tell your stakeholders. When you can clearly answer the question “what do I want the audience to think or do at the end of the presentation?” you have an understanding of what you are trying to achieve with the presentation.