When camping I keep my panniers in my tent vestibule and my bike locked to my tent.
For other times, I came to the conclusion that it's futile. The only thing one can do is to keep the bike in sight at all times. If this is not possible, then you must keep it somewhere locked or guarded, like in a hotel room, or ask someone to watch it. Sometimes if I have to go somewhere for a few hours I have paid a restaurant or hotel to keep the bike in their building. I also carry a full sized u-lock on tour. Very heavy but I suffer through it.
There is an old video of someone who had their bike stolen in Mongolia. They were sleeping in their tent and woke up to the sound of their tent being ripped in half. They sat up and saw a man riding away on a horse with their bike and half the tent dragging behind.
Last edited by Yan; 11-17-22 at 02:52 PM.