Factors Affected for Low Performance of middleware Messaging Softwares

Question

I am planning to inegrate messaging middleware in my web application. Right now I am tesing different messaging middleware software like RabbitMQ,JMS, HornetQ, etc.. Examples provided with this softwares are working but its not giving as desired results.
So, I want to know that which are the factors which are responsible to improve peformance that one should keep in eyes?
Which are the areas, a developer should take care of to improve the performance of middleware messaging software?