We do pre trips here, but just a quick walk around to check lights, signals and note any (new) damage left from the guys parking the night before. Just how do you tell if lug nuts are loose? I do a visual but can't say I check the lug nuts very well, now I'll pay more attention.
First you need to make sure the wheels have been painted and are in good paint repair, Then you can look at them daily to see if there is any sort of discoloration around the nuts, this will generally only happen if they are loose, if you notice it then check it by hand and write it up in the DVIR.
Just so you all are aware, those centers with pas/edd have a promt in the DIAD asking if you have done a pretrip and signed off the DVIR book, If for so reason you have a problem that is linked to not doing a proper pretrip and you have answered yes to these questions, you could be looking at a falsification of records and/or failure to follow instructions.
I simply do not understand why people insist on putting themselves in the line of fire by not following the methods that are taught to us all.