A lovely tutorial. I started using Dungeon Scrawl and it is super useful in making my games! I have even used it for games like Call of Cthulhu which has helped me cut down on prep time!
I wish I'd found this half a year ago when I started using Dungeon scrawl and had to teach myself, very nice guide! Only issue I've had between DS and Roll20 is grid alignment. Even after using Roll20s 3x3 grid detection and alt dragging the alignment it still doesn't align well for big maps :/
