I tend to use double-sided PCB stock (the kind with plated
through-holes) which is a little more expensive, but lets me pull this
trick:

Topside Soldering!

A tech at work showed this to me some years back, and I've done it ever
since.  You need to get some liquid flux, and an alcohol bath to soak
the board in to clean it when you're done (I use Tupperware).  Hold the
board right-side up (in a vise, or with standoffs in its mounting
holes), brush it lightly all over with the flux (use a small brush (acid
brush, old floppy toothbrush, etc.) and not so much that it drips).
Stuff the low-lying components (resistors and such) first, and solder
them in without turning the board over.  Add higher ones, repeat.

The extra flux will let the solder flow a little longer, and with some
practice you will get a perfect shiny joint top _and_ bottom.  Use a bit
more solder than usual, and a bit higher temp.  I usually use 750F.  A
reasonably temperature-controlled iron helps, my favorite is the Weller
WES50 (now WES51), an absolute steal at ~125 $US.

Most components can be done like this, (you can sneak in under most
connectors, sockets, etc. and get one pin, so it holds when you have to
flip it over to do the rest more easily.

I use flux with _everything_ now, and I can't believe that is is so
rarely mentioned in soldering tutorials.  With fine solder (<.050 - I
use .020 usually) it makes the job fly by with no rework needed.

Do others use flux for through-hole as well, or is it usually just for
SMT?

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