Thanks everyone for your wonderful comments and patience! The love-hate relationship between my camera and my laptop is back into the "love" phase, so here's the tute for the pants.
Why just the pants? The link to the hat-making tute is at the top of the first post of this thread, and to make the shirt you just outline an existing little shirt over your soon-to-be-reconned big shirt, cut around it, and sew the sides together inside-out. Hem the bottom and the armholes (or add ribbing/bias tape made from a strip of fabric from the same shirt) and you're done, since the neckhole is already there. If you look for resized shirts in this board, there are many other Craftsters who explain this better than I can, and they have some great pics, too!
On to the tutorial:
The short version for those who recon stuff all the time:
1. Trace pant to sleeve. Flip over and repeat on other sleeve.
2. Sew up the crotch.
3. Put in your waist elastic.
The long version for the rest of us:
If you already have a pair of pants roughly the size of the ones you want to make, find them. If you don't, you can totally just wing it.
1. Lay your first shirt sleeve out nice and flat, and place the folded up pair of existing pants over it. I wanted to make pants that were bigger than what I already had, so I placed them up higher on the sleeve. If you want shorter ones, just place them lower. Then cut around them, starting by the crotch and then up over the waist (unless you're a lefty- then you might find it easier to cut from the waist first- just remember not to cut into what will be your inseam after you get to the crotch area). If you don't have an existing pair of pants, just cut this same rough shape:
2. Now set your existing pair of pants aside, and focus only on the recon. Ah, sweet victory over store-bought clothes... I mean, lay your recently cut sleeve/pant over your remaining uncut sleeve mirror-style (meaning you have to flip your cut sleeve over before you put it on your uncut sleeve) so that your cuffs line up. Cut around it so that you have two pieces like so:
3. Sew your two pant legs up (right sides together) starting with whichever side you want to be the back. Actually, it doesn't matter where you start, but the way I see it if I start at the back, I'll have figured out how to make a decent stitch by the time I get to the front. Either way, you've made one seam that goes down towards the crotch and then back up from it (i.e. you stitched on the curved line of the pants, not the straight line of the waist part). A picture is worth a thousand words:
In the above pic, the scissors point to where you start sewing. All I did in between this pic and the last one was slide my pants legs closer together and fold down the front flap of each piece. It will make total sense when you're making yours, and if not, PM me- I'll be glad to elaborate.
After you sew the crotch seam, you should have something that looks like pants!
With an unfinished waist seam, that is. In my case, it helped to trim off the top to make it even:
4. Put in your waist elastic. There are tons of ways to do this, but the way I like is by making a casing, so I'll show you that here. First, I fold over about 1/4 inch of the waistline towards the inside of the pants and sew a line all the way around (like the first part of a hem). Then, I get my piece of elastic. I think the stuff I used was about 3/4 of an inch wide (use any you like/have on hand), and at rest it was shorter than the waist by about an inch or so, so that it could stretch plenty w/o being too tight on baby or falling off his diaper. The nice thing about making a casing for your elastic is that the elastic isn't sewn in, meaning if you don't like the finished product, you can just cut a small hole on the inside of the pants waist, cut and pull your elastic out, then fish a different sized piece back in until you like the fit. Now that you have your elastic, sew the ends together (with several seams, nice and tight) so that you have a loop. Put part of the loop inside the pants, near the waist edge, then fold over the top of the waistline to totally cover the elastic PLUS your previously sewn seam. In effect, you will be sewing directly overtop the first waistline seam, and NOT sewing over any elastic, like yay:
5. You're done! Lay out your uber-cool new sleeve pants (thanks to craftster rostitchery for that great term!!) next to your original pants and admire your work.
Please let me know if I've missed something, or if you make these and know a better way- especially if you correct me on something, I'll feel like my toes have been painted instead of stepped on.