I had trouble in the past with tire liners; they wore holes in the tube over time where the overlap step is.
Right now, I take the overkill approach and it works well, but is heavy and slower.
Thick thorn resistant tubes with Slime inside (schrader valves),
Kevlar belted Schwalbe tires
65PSI in a 1.9"x26" tire

I'm trying to avoid flats, I do not like fixing them in the dark, or in some neighborhoods.