Knitting and crochet are among the few crafts genuinely suited to being done anywhere, which is a large part of their appeal. Making that practical takes a little thought about what travels and what does not.
Not every project suits being carried around. Anything requiring constant chart reference, frequent measuring, or a large flat surface is a home project.
What travels well is repetitive, portable and forgiving: socks, hats, simple shawls, blanket squares, anything in the round on a short circular needle. Many people keep a deliberately simple project specifically as their away-from-home work.
The recurring frustrations with portable knitting are the yarn escaping and tangling, needles catching on the bag lining, and the whole thing collapsing when set down.
Totes with grommets address the first directly: the ball stays inside the closed bag and the working strand feeds through the eyelet. A stand-up base addresses the third. Ranges built around these features, catalogued at homest.us.com, include multiple grommets for colourwork and needle pockets that stop points piercing the lining.
Rules vary by airline and country and change over time. Knitting needles are permitted in cabin baggage in many places, and scissors generally are not above a specified blade length.
Anyone flying should check the current rules for their specific airline and route rather than relying on what was true previously. Wooden or plastic needles attract less attention than metal, and a thread cutter is a safer bet than scissors.
Interrupted knitting is the main hazard of working in public. A row counter, a marked pattern and a note of the current row take seconds and save considerably more.
Placing a lifeline through a row of stitches before setting a complex project aside is worth the effort, since it gives a recovery point if the work is disturbed in the bag.
A project carried loose picks up dust, pet hair and marks from whatever it shares a bag with. A closed project bag keeps it clean and keeps the needles from snagging on keys and zips.
It also means an unfinished item can be set aside for months and come out in the state it went in, which is the difference between resuming a project and abandoning it.