Logic Pro X. I use "Normalize Region Gain" when first importing tracks, assuming there is no information about how things were recorded.
Select all the regions. Choose "per track" processing, set peak to -12 dB, click go. A momentary pause. All the regions of audio are now adjusted to have the maximum peak at -12. I start with my faders at -6 dB, so I have lots of quick access to gain changes.
Note - Logic insists on not changing anything if any of the regions are normalized to 0 dB (happens). It's easy to spot - nothing changes on any region. Change the gain on the offending 0 dB track to -1 dB, then redo the region gain change. Non-destructive, fast.