Did you know that your settlements can run out of room? Yup that's what that Size meter in the upper right hand corner is all about. As it fills up, your space becomes limited and you can afford to put less items on your land. Food seems to have the biggest effect, so if you're using a particular settlement as a specialty farm for specific crops, you may want to keep this little trick in mind to maximize your available space.
Note that you will need to invest in both levels of the Scrapper perk for this exploit to work. When you come across weapons you do not need, store them in your inventory, then fast travel to a cramped settlement. Drop all the guns on the ground, then scrap them. The more complicated the weapon is, that is, the more mods it has, the more components it will give you. As the item is dismantled, it will free up a small amount of space in your settlement meter, more than it took up by being placed on the ground.
This is particularly easy after a settlement has been attacked, as many guns will be lying on the ground. It's one of the best ways to get necessary components for modding without having to travel far or take up a lot of stuff in your inventory. As you can see from the image above, you can get a lot of items from just one weapon. Go try it!