Give your reclaimed boxes and bags a sturdy, comfy grip by adding wire handles....

https://isabellassplendidcolumn.evergrovio.com/posts/how-do-i-make-wire-handles-comfortable-without-bulky-foam

Give your reclaimed boxes and bags a sturdy, comfy grip by adding wire handles. Use 2-3 mm galvanized wire—it’s strong and resists rust. Drill 3-3.5 mm holes near the edges for easy threading