Can driveway fabric (petro-mat) be used DIY?
I talked to one of the petro-mat sellers and found out that the standard petro-mat needs a liquid &quot;tack coat&quot; poured down before the geotextile is put down.  Typically the fabric is put down with a special machine.  To put it down manually would ideally involve four people, one standing at each corner, because if folds or wrinkles form, the piece has to be thrown out and you have to start fresh.  One could do patchwork, with reasonably sized sections, to make it more workable.  But the tack coat is very hot asphalt with no gravel, I think -- which is beyond this DIYer.
Some more googling led me to another type of petro-mat that doesn't required the initial tack coat.  For this one, you just clean the driveway thoroughly, fill any cracks at least half an inch wide, and lay it down.  It sticks to the driveway and stays put nicely while the asphalt is being put down.  Description:

The GlasGrid System capitalizes on the high tensile stiffness of fiberglass. Its grid configuration features fiberglass strands coated with an elastomeric polymer. Each strand has a remarkably high modulus of elasticity that makes GlasGrid stronger than steel by weight.
A pressure-activated adhesive coating on the underside of the grid makes GlasGrid one of the fastest-to-install interlayer systems.

I plan to make an appointment with a residential paving service to have a new layer of asphalt put on my driveway.  The previous weekend I will clean it thoroughly, use a knife to clear out the bigger cracks, fill them with the DIY crack treatment, and then the day of the asphalt appointment, I will lay out the glass grid geotextile and stick it down.  I'll let the asphalt people do their regular thing.
I think that the occasional small depression should get evened out through the normal paving process, so I don't plan to do anything to those spots in advance.
The challenge now is to get a small piece of glass grid.  It comes in very large rolls since this material is not currently marketed to the residential consumer.  However, one of the sales people connected me to a paver three hours away who works with glass grid, and he has agreed to send me a remnant next time he has some leftover from a big parking lot.  (None of the pavers in my area have the slightest idea geotextiles even exist.)