You use a lot of the tricks I do already.
It sounds like we run similar tables and games, so I will tell you a few of my immersion secrets.
1: Everyone the players interact with is unique. Different looks, different attitudes, different names. If they get a soycafe, they got it from "John, the pimple face Ork barista."
if they live in an apartment building, then they know their neighbors; It s not that troll couple, its " Sarah and mike Thompson, Trolls.... and that means you try to stay out late every Tuesday night, as that's the Thompson's 'Date night" and the walls in your place are paper thin!"
2: Know everything about the block on which the players live. what businesses are around there? what are the people like? is there a gang problem? are THEY the problem? All this matters, as it builds up the world in the player's minds, it pulls them into the world, and makes them care. And when players care, the fun really starts

3: Contacts are two way streets! Just as the players go to Contacts for help, Contacts should be coming to the Players! It makes that connection and loyalty rating a wonderful two edged sword

So you have "Mario, the Mafioso" as a 6/6 contact huh? Well, guess who calls you at 3 am and says he needs you, 10 meters of tarp, a shovel, and a car in 60 minutes..."
4: If something grabs your players attention, focus on it! If a player shows an interest in some random NPC you threw in for color, then maybe that NPC should start playing a larger role in your game, even if that just in subtle little ways at first. Sammy really took an interest in that secretary from that job last week.. maybe she makes an appearance at the club just before or after a meeting?
The Plots and Missions you design are all well and good, but its the Missions your players create for themselves through the interactions with your world that will be the adventures they remember the most! And if you can take what they are (literally!!) Spoon feeding you and make it come out as something you planned all along, then your doing your job right