Seasoning with Colons and Semi-Colons.

I think my problem was that I was using them as pauses, and worse still as a cheap way to show a link between two ideas without actually demonstrating the link. This is a common fault in bad academic writing (particularly in Derrida rip offs). It is a stylistic workaround for not being able to prove what you are saying. In the short term, learning to write without semi-colons and to minimise the use of colons forces you to provide a clear a constructive argument.
However, in the long-term, there are occasions where the colons and semi-colons are both better and more beautiful. So how are you supposed to use them?