Granted it is X, but …: X + thì + X, nhưng …

Saying a word twice, with thì between, grants a point before you object to it, like "sure, it's …, but" or "… it may be, but": Đẹp thì đẹp thiệt, nhưng mắc quá. It's pretty, sure, but it's too expensive (in Hà Nội, đẹp thật, đắt quá).

The first half admits what is true, often what the other person has just said. The second, after nhưng or nhưng mà, is what counts for you. Thiệt (really; in Hà Nội, thật) after the repeated word makes the admission stronger, but is optional: Gần thì gần, nhưng đường hay kẹt xe. It's close, sure, but the road's always jammed.

The repeated word is usually a describing word, or a verb such as thích (like): Thích thì thích, nhưng em không có tiền. I like it, of course, but I haven't got the money.

You know thì after a topic, and Đi thì đi! on its own as a shrug: fine, let's go. Add nhưng and you agree with a condition: Đi thì đi, nhưng em về sớm nha.

Mặc dù … nhưng (although) states two facts evenly and suits writing too. Có điều weighs things the other way: Đẹp đó, có điều hơi mắc (in Hà Nội, đắt) still likes it, with one small catch. After X thì X, the objection wins.