An informative essay’s conclusion should

connect back to the thesis while summarizing and extending the main points.
introduce a new subtopic of the thesis that has not been discussed yet.
explain to the reader why the content of the essay is of importance.
restate the essay’s thesis statement exactly as it appeared in the introduction.

A.  connect back to the thesis while summarizing and extending the main points.

When constructing a conclusion, it is important to keep in mind that there should never be any new information introduced.  Thus, you wouldn’t want to begin to discuss a new subtopic.  Additionally, because the conclusion should serve to wrap things up that have already been discussed, you would not want to provide additional explanation as all explanation should be presented within the body.  Lastly, even though you would want to restate/reiterate the thesis statement, you will need to do this with different wording; as such, never restate the thesis word for word.  

gatsby's clothes have a symbolic meaning, as the use of colour and fabric in his clothing demonstrates his hope, dreams, and wealth. gatsby's clothing symbolizes his wealth through his torn shirt, his silver and gold suit, and his english shirts.

the italian poet francesco petrarch did! (: