I wanted to start a thread with some info that a lot of us know, that maybe some don't. Community sharing and such. I know a lot of this most of us have stumbled on, but don't be a hater. keep it positive and helpful for those who haven't.
To start, a while back I contributed to a thread about how it was driving us all crazy you cannot move walls up and down easily, and the corner peices drove the wall into a weird angle we didn't want. We couldn't turn sharp corners at a 90 degree angle.. Like, if wrapping a wall around a settlement, you get the floating problem too, sometimes so bad I used to see raiders straight walk under it. So I stumbled onto a solution for this that again, I can't stress enough that I know most of the community knows but let's share and be helpful for those who don't.
So first, the turning the corner issue. So what I have started doing for walls, is putting a foundation first, followed by walls on top of it. I use first wood floor, and shack foundation 1 (the one with concrete). When you use either, the walls will snap together properly, and by doing this you can turn any corner at a 90 degree angle.
As for the floating wall issue, which I know we all have had the pleasure, if you use shack foundation one it will clip for you thereby placing "a slab of concrete" beneath the wall preventing anything from strolling or shooting underneath it. To do this you want to use the normal shack foundation FIRST, building your perimeter and then replace floating parts with the concrete or use no wood floors and just drop the concrete parts (which I found more annoying when trying to get the shape I wanted)
I do this at Red Rocket to use it kind of as a personal HQ with few settlers and companions I am not using. I put a couple screens to show you what I mean with the sharp corners and blocking the gap.
http://i.imgur.com/YlkbeEb.png
So another thing you should know (that again, I am sure most do), is you can buy a house in DC which is awesome to avoid rads storms and to have a zero threat place to chillax and do what you need to.
There is a second image that doesn't want to show up it seems. I will try to get it upload in comments so you can see another angle.