There are three major types of frames: Wedge with split or solid bottom bars, slotted frames, and grooved frames. The wedge style frames are nice for wired foundation since the wedge traps the top of the wires and holds them securely. Slotted tops are the easiest to use, just drop the foundation in. Grooved frames are a bit more fiddly, but work great with plastic foundation.
I make my frames as follows:
Find a nice 2 x something that is flat or very nearly flat. Cut to 19" lengths. Set table saw to cut the taper on the end, or 3/8" if you want a flat end to keep hive beetles out of the space (but the bees glue them down more). Cut both side across the end. Set fence to width (1 1/16" for standard frames, 7/8" for narrow frames) and rip the 2 x across the width. You end up with proper width sections with two tapers. Set the saw to exactly split these in half, should come out a bit less than 3/4". Cut dados on the ends to hold the end bars, exactly one inch from the inside of the dado to the end of the bar on both ends.
It really helps to have a band saw for this job, as it give you an extra bar out of a 2x6 or 2x8 and they will be a hair thicker too. You can use a narrow kerf blade on the table saw too, I do.
Of end bars, plane some 2 by stock down to 1 3/8" or 1 1/4" (standard or narrow bars) and cut to the correct length for whatever size you are making (deep, medium, shallow, Dadant deep, whatever). Mill a slot with a dado set down the center to fit the top bars you made (measure -- should be about 3/4" for the narrow and 7/8" for the standard, but mine vary a bit). Mill whatever slot you want on the other end for your bottom bars - -I like split bottom bars and use 3/8" x 3/8" bars, but 3/8" x 5/16" works fine too.
Slice these blocks to make the end bars -- make sure they are the same as the dados you cut on the top bars so they fit tight but don't split things.
Cut bottom bars to fit whatever you cut in the end bars.
I find that I set up a pile of wood in blanks. That way I can set up a cut, get it exactly right, and crank out a pile of parts. Do one operation at a time and process the whole batch -- stay awake, it's BORING, and watch that you don't machine your fingers too!
I have a ton of frames to make -- plan on a three more hives next year, so that means 100 narrow frames (33 deep and 66 medium, plus a few) and I'll need at least 80 standard shallow frames for honey. Gonna be a lot of sawdust in the shop this year.
I do really like narrow frames -- the bees seem to build comb really fast on them and keep it flatter than "standard" frames. Fill it up with brood, too, top to bottom.
Peter