this and that; various things
そんなこんなで話が長くなった。
What with one thing and another, the conversation went on for a long time.
そんなこんなでいつの間にか仲良くなっていた。
Through one thing and another, before I knew it we had become close.
引っ越し後のそんなこんなを経て生活が落ち着いてきた。
After going through all kinds of things after the move, life has started to settle down.