Sit alongside another person, in real life or on video, while you both work on your own thing. Their presence anchors yours.
1/3 Pick a buddy
A friend, a colleague, or a complete stranger on a body-doubling app like Focusmate or Flow Club, all of these work just as well.
2/3 Set a timer
Agree a window before you start, many people find fifty minutes works well. Say what you're each working on at the top so you're both anchored.
3/3 Stay quiet, stay visible
Don't chat your way through it, it works because you are both working, not talking. If you are doing this online, many people find it helps to keep cameras on.