A T-shirt and a pair of jeans is too casual for a dinner date. But matching your jeans with a lacey top would make a difference. Lace adds femininity and elegance, making the jeans look less casual. This casual but not too casual look respects your date without overdoing it. Another good thing about this look is that you don’t have to wear high-heels. You can wear loafers or even converses in matching colours. Leather or faux leather ones can make the look classier.
This is the pair of shoes I wore: glittery silver leather loafers. The glittery silver leather makes it even classier. By the way, they were brand new. It was my first time wearing them.
Just some personal sharing.