i used this tutorial, which was super clear. it took an embarrassing amount of head scratching though to figure out how to make it (faux) leather bottomed (i blame that glass of wine with dinner). if you're interested, i'll try to explain it here.
the tutorial starts with a outer fabric piece 13.5 by 17 inches, so to make it leather bottomed i cut the leather 9.5 x 13.5 inches and then the two grey cotton pieces 4.375 x 13.5 inches. lining up the 13.5 inch sides, i sewed a grey fabric strip to either side of the leather with a quarter inch seam allowance. with these dimensions, the leather is actually over-sized by a quarter of an inch, but i didn't press the seam flat. rather, i rolled the leather a bit and top stitched it where it meets up to the cotton. this takes up the extra length. i wasn't actually sure this would work out, but it did for me. once pieced, you could always trim the whole thing back to 13.5 x 17 if it's too big.
sorry if that doesn't make sense...
i was really glad to use some more of the spoonflower fabric i designed. i've been hoarding it for awhile for special projects. this is the same woodland print as margot's tiny backpack, but in silver.
the bag is lined with some sweet buffalo plaid flannel, which i now have more than five yards of thanks to a bit of an impulse purchase (and a really good deal!). i also bias bound the seams with some vintage mustard yellow bias tape that i got at a thrift store. mustard yellow goes with everything.
i'm still pretty terrible at sewing with bias tape, but i think i'm getting better. i think part of the terribleness is that i pick really tricky projects to do it on--ones with super bulky seams. i also still can't figure out interfacing. when i use the heavier stuff, i find that the fabric looks nice and smooth when i i start, but by the time i've sewn it up it's all wrinkly. maybe that just means i should use a lighter weight interfacing. all in the name of progress i suppose.
the finished bag is a bit giant. roughly 4.5 x 4.5 x 9 inches. more than enough room to carry all of my school supplies. probably enough room to carry a guinea pig, or a small rabbit. that would make for an interesting class...