Php 4:8 Whatsoever things are lovely.
The Bible actually doesn't say much about lovely. The lovely you'd expect is in Song 5:16 - his mouth is most sweet, yea, he is altogether lovely. This is my beloved, and this is my friend, O daughters of Jerusalem. I like this verse, because "This is my beloved, and this is my friend" is engraved on my wedding ring, from Krista. So for me, anyway, lovely thoughts all go toward her! :) If you married, your spouse would be a great object of lovely thoughts for you. Song of Solomon can help you out with the poetry part, if you need help like I do. If you're not married, keep reading; you have other options!
You could go the route of music. Eze 33:32 compared the Word of God to a lovely song, a pleasant voice, and a skilled instrumentalist. The application would need to be different from this verse, where the people heard the beautifully presented words, but didn't do them. The point is, you're thinking about them, so you'll do them. In the NAS, the dwelling places of the Lord are lovely, and His name is lovely. Think on those!
The third lovely is in David's song for Saul and Jonathan after their death 2Sa 1:17-27, calling them lovely. Jonathan, definitely, but Saul? David met Saul after God has rejected Saul - how could he have been lovely? Not only that, he calls them pleasant. If that's not a forgiving spirit, I don't know what is!All verses in this article