Shift the load to one arm and march toward the one-arm pull-up.
Keep the supporting arm as straight as possible, the straighter it is the harder it works.
The archer pull-up loads one side of your back at a time: you pull your chest toward one hand while the other arm stays long along the bar, shifting most of your bodyweight onto the working lat and bicep. The straight arm is not resting either, it is doing brutal straight arm pulling work of its own. This is the standard bridge between strict pull-ups and the one arm pull-up.
You should own strict pull-ups for comfortable, controlled reps first. If regular pull-ups are still a grind, archers will just teach you to kip and twist. Build volume there before shifting the load to one side.
As little as possible. The straighter and longer that arm stays, the more of your weight the working side takes. Bending the support arm is the most common way people accidentally make archers easy.
Archers pull up toward one hand and lower back down. Typewriters add a slide across the bar at the top, which increases time under tension but is harder to do strictly. Master clean archers on both sides first.
