You've got good answers so far. The problem, as other's have alluded to, is your characterization of the question:
"
I'm sure they don't really want holes all over."
Well SURE!

And if you intend to
leave "holes all over", then you need to return to detecting 101 class, and learn how to leave no trace of your presence.
Sure, this involves some psychology, because while you may know you'll do no harm, leave no trace, etc.... the fact is, if you show up at someone's front door with a shovel, and throw out words like "hole", "digging", etc.... then what do you expect? I just say this: "you won't even be able to tell I was there", and leave it at that. In this way, no talk is made of any interim necessary evils (probing, prying, popping, digging, or whatever you want to call it).
And here's another trick: If you perceive that someone is watching you from their windows or porch (a natural for someone who's just granted you permission, of course), be sure to START with shallow pennies and tabs. Ie.: the signals that blow your eardrums off, and you know it's going to be a tab, or quarter, at 1/2". Just probe it out with your screwdriver (no hole) and hand it to them. Do this with about 5 tabs and a surface penny or two, and guaranteed they'll get bored watching, and go back in their house

THEN you can do some of the more iffy deeper ones.