Sometimes, I will even toast a really good bagel and then nobody wants it...I hate that!!
So, now I keep a paper bag (really important that it isn't plastic because plastic might retain moisture and cause mold). Keep it in a dry place (in a corner of your kitchen away from any moisture - dark and dry is ideal).
You can put anything in here; the ends of your bread loaf, half bagels (as long as there is no butter on them), crackers, etc...
If possible, cover it with another paper bag or cover it with a tea towel because it will take a while to dry so you don't want dust or anything else to get into the bag. And, considering this is stuff that would have gone into the green bin, isn't it nice to know you have just made something from nothing??