Adding presets in Lightroom without resetting initial adjustments

This is a long-discussed issue: presets work in an absolute way (by imposing a stated number ONTO a certain slider, ignoring its previous value) rather than in a relative way (by increasing or reducing the previous value for that slider, BY a certain number) - though this will not always produce, in practice, the same perceived amount of change.  

Lightroom / Lightroom Classic / ACR do not now - and may never - offer the option of a true relative preset. 

There are other ways to make a relative change, though:

• In Library is the Quick Develop panel: here you can nudge Exposure, Temperature or whatever, up or down, by a certain step amount (enabling AutoSync makes it so that all other currently highlighted images receive this same nudge as well). 
• Tone Curve. This sits independent of Basic settings. Besides tonal change, RGB channels are separable in Tone Curve making it very similar to a Curves or Levels adjustment layer inside Photoshop. So you could apply the same midtone darkening / reddening / contrast enhancing Tone Curve "look" onto multiple photos, and this will have the same relative effect onto each one. However this cannot do e.g. Clarity, also note that this constitutes post-processing which (in technical terms) can degrade an image's content but can never improve that content. This is because it has no access to the source picture data, only to whatever the other current adjustments are making from that - hence tone curve alone would be unable to retrieve any currently blown-out detail in the whites, for example.
• Local adjustments are relative in their nature. These don't have to only be localised, e.g. a gradient filter can be made to cover the whole image, applying certain relative adjustments - and then when synced onto other images, this will have the same relative effect there too. Local adjustments don't operate as post-processing in the same way that Tone Curve does, though: quite the reverse. They pre-modify the input which each image's Basic panel adjustments are then working off.
• A modified profile could be made and selected, which then (as a constant change), achieves a different end result out of these various images' individualised Basic slider settings.

It all depends on what settings were checked when creating the presets.

If, let's say, the exposure is left at 0 but is checked when making a preset, it will always reset to 0 when applying that preset.

If, on the other end, you leave exposure unchecked, then you can change the exposure on any picture before selecting that preset, and the exposure will stay at your chosen value.

That is why, when saving a preset, you should only check the boxes for the settings you want to be affected, instead of checking them all.

" For example, there are three options 'Copy after setting to before', 'Copy before setting to after', and 'Swap before and after settings'.  Will any of these setting preseve my initial settings and than let me apply the preset?"

No, your initial settings will not be preserved. Those are simply options to copy settings for a single picture, similar to when you copy settings from one picture to another except it's from one develop state to another (i.e. within the develop history of that image).

Hope that helps,

Michael

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Michael Niessen - Photographer, photo-editor, educator