This is the latest mod I've installed (84 now) and I'm liking it enough to put it here:
http://www.nexusmods.com/fallout4/mods/17507/?
Scavver's Toolbox. It allows bulk scrapping of junk items. Any amount from 1 junk item to thousands. I scrapped the junk in my Sanctuary workshop, which weighed over 24,000. You craft the toolbox, drop it and activate it. A menu appears and you can move items in and out of the toolbox (including all junk items in one go). Select the scrap option and every junk item in the toolbox is scrapped, the resources are transferred to your inventory and so is the toolbox.
No more settlement workstations containing 76 broken lightbulbs, 18 dumbells, 97 footballs, etc, etc. Particularly handy if you're developing an unprovisioned settlement and want to take resources to it. Just make sure you haven't got any junk items in there that you might want to keep or sell (undamaged items, unique items, pre-war cash, whatever).
You can take it with you when scavving and scrap stuff on the go to reduce weight. I don't because it seems a bit silly to me (I'm clearing a building with enemies in it...so I'll just stand there for a while disassembling desk fans and suchlike) but that's up to you.