Tote bags can be filled with a few items to be dropped off at the local charity donation center - and they will sell the tote bag, too.
I sort the ones we have - I keep the ones that *I* like and will use. I donate the ones that nobody will use. I have bought a couple of drawstring/backpack bags for use to store things where the original bag or box is gone (air mattress, sleeping bag, and so forth) to keep them cleaner & in one place with any accessories.
I bought a nylon "gauze" one to use at the gym & beach (the wet swim suit & towel can dry out a bit - and any sand falls through the holes in the "fabric"). VorGuy uses his leatherette "gym bag" for travel luggage, so a smaller backpack/tote is for his gym shorts, shirt, socks, & shoes.
As to the "lightly used" containers of salad dressing - the only way to make them acceptable for most food banks is to have them still sealed (not used at all) - so setting aside a couple of the bottles that are going to be the least likely to be used would be the only way to handle it.
Or take them to another potluck dinner, if you know someone who eats more salads or is likely to have a couple of salads on the buffet table.
I've been known to buy the tiniest bottles I can find of dressings that we don't use, so that company can have their favorite - but I don't end up with a bottle of dressing that is going to take three years to use up.
I have a husband who teaches high school - I've been known to take things to the fridge in his conference room/computer lab to be used by the students who are using their lunch period to do homework, computer research, or talk to friends in the area. The fridge gets cleaned every semester, so even if they haven't eaten the Ranch dressing - it will "go away"! And leftover desserts.......those rarely last more than one day.......the pan has been known to come home with the brownie crumbs having been cleaned out of it.