Powerpoint presentation

I have put together a powerpoint presentation which is due to be sent off early next week. However after showing to my designers (not powerpointers) and other experts, it has been described as anything from slightly amateurish to bland.
In short I am happy with content but layout and graphics need to be brought to life. It is approximately 16 pages.
I can be available to liaise over next few days in order to give feedback although the project will be allocated today and must be ready to send off Monday evening.