Just to help you fellows ou there learning this difficult language... as a native speaker I can adfirm you that elision is totally optional but nowadays we tend to use it with some expression such as "c'è" or "cos'è?": you will never find written anywhere " ci è" etc..
Apart from that it is gradually becoming unusual to put the elision when the last vowel of a word and the first of the one which follows.are different: whilst senz'acqua is pretty usual, senz'effetto, for example, is more easy to.be found in literature than in casual writings. Remember always not to.put the apostrophe.when there is "troncamento": e.g. qual è? Hope I helped