A short tip in case you’re using a digital camera - mirrorless or similar - with an adapter to mount a manual focus lens.
The common way to perform manual focus with mirrorless cameras is to use focus peaking and focus magnification.
This approach gives mixed results, as the focus peaking highlighs hides the image details while focusing, sometimes becoming visualy too intrusive and blocking the subject.
The alternative way is to set the camera JPG sharpness to the maximum available value. When doing this change, the EVF and LCD will give you a better representation of the plane of focus, on some cameras it will increase the visibility of the moire pattern. You can use focus magnification in lower contrast scenes to better see where the focus will fall.
The above setting will make the JPG oversharpned, but RAW output will have no change. I set the camera to RAW only, but effect will still be visible on the image preview.
By using this approach the number of in focus photos has increased allot for me.