We start with an ordinary paper bag from the grocery. This one happens to have handles, which will have to be removed to ease the process. If you bag has no handles then skip ahead to step 3
let the folding commence. But first you may find it easier to mark where your folds will be. Usually there is a place pre-folded near the base, so mark that one and then mark half way between that and the top where there opening is.
Fold at the top mark first. It may be helpful to fold one way and then fold back on the same fold in the opposite direction.
Now unfold and open it up because we are going to implode the bag by folding it into itself along the folds we just made. Start at the top mark and fold into the bag.
Repeat folding inwards on the lower mark now. It may be trickier this time since we reinforced it.
Hey, now it's tall enough for magazines! Unless you have years worth of subscriptions, however, they are likely to slide, bend and fold like a wet noodle. Onwards to further reinforce and make compartments to separate and add some standing stability.
close it and fold it up as if to flatten it out (the same way in reverse when they take it from a stake of paper bags at the market) but don't gold it up all the way.
Instead of folding the base flat against the side of the bag as usual, fold the base down and in half, like so.
That's it! add your comic books or whatever.