Closing deals is a basic sales skill. If you are having problems closing a deal you need to figure out why. Then you need to pinpoint the problem and fix it.
For example, if you have a tendency to speak in a monotone or speak too fast, you may be undermining your own effectiveness. So, practicing a better "sales voice" could prove helpful as skill in communicative ability is often closely associated with closing a deal.
Verbal delivery is just one example. You may have different things you need to look at. They key is to discover the flaws and work on improving them.
If you are having difficultly determining your flaws,you might ask a trusted friend or colleague. You might need to role play to do this. If your friend is honest and trustworthy, they’ve constructively point out your errors. They may even be able to give you some pointers.
Of course, in order to do this you need to be open to criticism. Being overly defensive will eliminate the ability to improve. Instead, be open-minded about your flaws and seek to correct them.
Related to closing a deal