One of the things I am doing that I thought was clever, but perhaps, not so much, is including my price in the ad copy, on the premise that I don't want to pay for clicks from people who aren't willing to buy. Perhaps that's optimization that's better left for another day, however.
You may already know this, but on the off chance you don't: if you match words in the query in your title or text, Google will bold them for you, which tends to increase CTR something fierce. You can do this with dynamic insertion ("Google it") or by organizing your ad groups in a thematic fashion, which is something you should be doing anyhow.
Pretend you're a pet store. If you dump everything into one ad group and write generic copy, it will typically not get bolded. If you segment your ad groups well, words about dogs in group Dogs match ads about dogs (thus bolding the ads), words about cats in group Cats match ads about cats (thus bolding the ads), etc. Plus since folks are in a searching mood you should make it abundantly clear that you have exactly what they are looking for. (Goes for the landing page, as well.)