Make a bag for your schoolbooks, gymclothes or whatever you need. By having a clear window you will easily see what's inside. You can make this any size you want, even making the window in a different shape. Make smaller ones to sort out your stuff or how about your laundry? Add pockets with or without zipper for extra stuff like keys or money. I made this one pretty basic so you will get the idea. It's supereasy to make so don't be intimidated if you're a beginner. The straps are long enough so you can wear the bag under your armpit and the bag is big enough to carry any standard sized notebooks. You can use standard cotton fabric and the bag will still be sterdy because you use 2 layers of it. I've carried mine full of librarybooks for months and it's still whole.
Stuff you will need:
*2 coordinating cotton fabrics: 50 cm each (and the usual width which usually is 140-150cm)
*a piece of soft clear plastic (like the one you use as tablecloth.) 27x15cm or depending on what size your window is.
*Basic things like sewing machine, thread, iron, scissors, ruler and some pins.
I've included seamallowences in the measurements. They don't have to be exact. I always use the edge of my foot for standard sewing and then a mark on the foot for the narrower seams. Just make sure you use the same seamallowences and you'll be fine.
0,8cm for the straps, sides and bottom of bag
0,5cm around the top edge
0,3cm around the window and reinforcements for the straps
Finished size of the bag: 36x37cm and 52cm long straps