well if you do
I highly recommend that INITIALLY you don't. So when you are first trying to get your ideas out make sure you put them in the most simple language. This is not the stage where you go to the thesaurus. Try and type it out the way you would normally talk in a conversation because usually that is when you communicate the clearest. Say what you want to say out loud then type that onto your computer (or write onto paper). Then play with the wording to make it a little more formal, and assuming clarity has improved you can then afford to swap in some fancy words (but make sure you know the exact definition and how to use the word properly).
secondly (this is for clarity in general, not just if you use fancy words in the wrong place) - make sure you are not overloading your sentence with multiple ideas (also why it is so important to say your sentences out loud as you can notice lengthiness/other faults so much easier). Try and stick to one point + technique and quote per sentence and if you do want to link the sentence to another point try using
(additionally, therefore, moreover) to begin the next sentence with that other linking point. That way you are keeping your argument logically progressing but also giving the marker a bit of break to take in each bit, hence improving clarity.
hope this makes sense
the irony if it doesn't :/