As pointed out earlier, Hardy makes location a major part of his novel. Each part of the novel is named after a different place, so you know he wants you to think about where these people are. Are they in the country? Are they in the city? Are they in their hometowns, or are they in a less familiar place?
The problem with each of these locations is that they contain people, and people come with both eyes and voices. No matter where Jude and Sue go—new places, old places, home, away—they find gossip and scandal, which is why they end up having to move around so much:
'But don't I get out? Aren't we going to stay here?'
'We couldn't possibly, don't you see. We are known here.' (4.5.7-8)
If only they could have made their way to Paris or London or some other giant city, they probably would have been just fine. But the towns they keep finding are small enough (and conservative enough) to keep tight watch on new people such as Jude and Sue.
Hardy also uses location to distinguish between the new and the old. Those who just arrive in a place see it entirely differently than those who have spent their lives there:
"Like all newcomers to a spot on which the past is deeply graven he heard the past announcing itself with an emphasis altogether unsuspected by, and even incredible to, the habitual residents." (2.2.11)
Jude tends to notice things about the places that they visit because he doesn't really belong to any of these towns—he hasn't spent enough time in them to get accustomed to (or bored with) what they have to offer.
Hardy makes sure we know what his characters look like. It's not that he spends pages and pages discussing clothing or hair, but he does enough to give us a sense of who we should be imagining. He takes special care to draw contrasts in physical appearances between characters he wants us to think of as opposites. Here is how he describes Sue:
"the pretty, liquid-eyed, light-footed young woman Sue Bridehead." (2.3.9)
Here is how Hardy describes Arabella:
"She may have seemed handsome enough in profile under the lamps, but a frowsiness was apparent this morning." (5.2.80)
The "pretty, liquid-eyed" girl vs. the frowsy (meaning messy and dirty) gal who needs excellent lighting to look okay in profile. Yeah, we think we can guess which one of these two we're supposed to like and which one of them we are supposed to despise. Hardy works in physical descriptions of both of these women throughout just to give us a sense of how different they are in every way, and it's an effective tool.