""a few reasons:
- this board only has metal on the bottom, so soldering a standard header would be tough at best. I suppose you could flip the board over, but...
- there's still that offset female header to deal with. a standard male header won't work because it's rigid and straight, and the holes don't line up.
- I like the idea of all the raw materials being readily available. some huge percentage of Americans (90%+ I think) live within 5 miles of a Radio Shack. male headers can be harder to come by. (Note: I realize that not only Americans are interested in this instructable, I just live here, and "
I didn't mean to imply that your way was wrong, just that a lot of labor and time might be saved using premade strip headers.
And anyone using an Arduino should buy a lot of strip headers for hooking up connectors, sensors, etc as just sticking round wires into the Arduino hearders does not make a very mechanically strong connection. Just a suggestion.
Oh, by the way I should caution that using strip headers on SINGLED-SIDED perf-board can be somewhat unreliable over time unless they too have some epoxy glue support added.
Inserting and uninserting the board repeatably from the Arduino will eventually loosen the bonding between the solder pads and the perf-board causing the connecting PCB strip to flex and possibly break. After having seen that on one I build to plug into a solderless breadoard, I now try only to use perf-board stock that uses plated through holes. It does cost more and harder to source, but I would rather build it only once. 
Lefty