Identify hole location, mark with sharp tool. Hammer and punch to create impression. Drill holes with small bit, patience and cutting oil. Drill hole to size with larger bit. Install threaded rivet nut with the “Brute” Rivet Nutter tool.
I selected to install three rivets in such a manner that allows a standard water bottle cage, a Salsa Anything Cage, or a Topeak Modula XL cage. Specifically, the Salsa Anything Cage must be located above the chainrings. The 64 oz. Klean Kanteen that I hope to use is too wide to clear the chainrings, but is narrower than the crank arms.
The standard H2O cage uses the lower two holes.
The Salsa Anything cages uses all three holes.
The Topeak Modula XL cage uses the upper two holes.
At the rear, I drilled into each seatstay to install a butchered Nitto mini-rack to be used as a Carradice saddlebag support.
The seatstay bridge had a small drain hole, which I enlarged and tapped for an M5 bolt.
I have a habit of drilling holes in new bikes. I installed water bottle mounts to my Surly Pugsley last spring. And, I drilled the seatstay bridge on my VO Campeur to accept a VO Pass Hunter rack..