Proper way to extend a street? (so that it doesn't look horrifically bad)

[indigo flax]

Well, probably either a turn, or a continuation straight forward, I think your main problem is lack of detail, buildings like these could have fire escapes on their sides, random cables, lights, dumpsters, trash bag piles, random debris, back exits from buildings, a floor which might have like a slight wedge in the middle for drainage, trash decals, puddle decals, dirt-concrete blend texture ground..

Graffiti

vents

maybe even shake up the geometry to not be so flat

[manic herald]

use reference photos

[indigo flax]

yes 👍

[manic herald]

check you didn't disable the grid

[wild forge]

this happens when you reload an autosave on launch after a crash or something

when it asks you if you want to load the autosave or whatever just say "no" and then load it normally

but yes use reference photos, use more props, etc