Shakespear 73 sonnet!?

This entire sonnet is an extended metaphor which compares the poet’s love to all those things that are near death. The first comparison is to a tree in late autumn when only a few withered leaves cling to the branches. Next the comparison goes to the twilight of a dying day when the sun sets and black night descends. The third comparison is to a dying fire where only ashes remain. The final one is to a death-bed . The sonnet can be interpreted in two ways. The first is that the speaker is really dying and realizes that he dearly loves those things and people that he must leave behind; the second is that only love is dying because it has consumed itself, but the speaker hangs on to it and cherishes it all the more because he knows that it will soon be gone. The last two lines also suggest that the beloved in this sonnet knows that his love is dying and clings to it (and him) even more tenaciously. There is personification in “boughs which skake against the cold;” also in “bare ruined choirs”.

There are comparisons within comparisons in this sonnet, but basically is is one large figure of speech. I hope this is what you meant by techiniques.