How do I steal workers from the AI on higher levels?

What is the general strategy for this? I know it is easy getting a city-states worker, but it is difficulty for me to get 2 workers from the AI. I play on Emperor-Immortal. Thanks.

On Immortal, send your starting warrior to the capital and explore around it while waiting for their first settler. Steal that, then any subsequent settlers/workers they produce.

On Deity, they will start with a 2nd settler. Once they've planted it, and the 2 workers they start with have improved the 6 tiles around the capital, they will walk towards the 2nd city. You catch them in between (though not if the tile can be shot by both cities and the unit is not a spearman or tougher) and then back out the next turn. Watch for warriors that can get in your way or kill you. If you back out of the range of the city and a warrior does not follow, heal there and hover (if the unit is not needed to escort the worker, which it shouldn't be). You may be able to get more by repeating the same thing. The AI is not clever about it.

My record is 6 from AIs and 2 from CS before T32. Good luck!

I kind of circle around the borders and see if I can get oneshoted if I go for it. If there's nobody around, definitely go for it. One thing to have in mind, a scout will not attempt to capture a worker and a city will not shoot at a worker so if there's a pair of workers doing some farms, feel free to nick them both. If the city kills your scout/warrior (might not happen if on full health), just run them both back for giggles. Then you can either nab another one from a different neighbor or simply from a CS. Or use that CS to farm workers, but it's important to do it before anyone else meets them and declare protection, that will hit you with a diplo hammer and the AI doesn't really forget CS aggression

Easiest way:
Trade embassies with your closest neighbor, having been tardy to found a city in their direction.
Have a fast unit on a hill.

When the AI sends its settler your way, DOW them, enslaving their settler into a worker.
Declare peace 10 turns later.

The best farm spots are on lux/horses that are 3 tile away from a city. It's very easy to farm there. Grab one then wait two tiles away not on a hill for another one.

After that it's mostly a matter of being patient and knowing if there's too much risk or not.