For the most part, trying to master any skill starts with carving out time to practice. On top of that, it's about finding slivers of opportunity in which to practice even more.
Waiting in line at the grocery store? Discreetly check for security cameras. Most big stores have them everywhere, but what you want to do is learn to spot them without looking like you're trying to find them.
If you're waiting for the barista to call your name for your coffee, scan the other customers as they go up ahead of you. You're looking for any obvious weak points. A limp. A cast on an arm or a wrist. Hearing aids or glasses with the thick, convex lenses that indicate farsightedness. A lot of people hold their car keys while they wait so you can get an idea of the make of their vehicle. With practice, you may even learn to tell what model. Again, discretion is key. Don't try to look like you're not looking. It's normal for people to look up at a loud noise, sudden movement, or someone shouting a name. Glance over like a normal human being, than return to what you were doing. Hold that image in your mind, that snapshot, and run your scan.
And don't ever pretend to do something else while you look at the person. If you ever see someone looking at you while they're simultaneously doing something else, they're either a cop or a serial killer. Best to just pretend you didn't notice them surveiling you and proceed as normal until you can get out of their line of sight. Corners are good. Get around the corner, and then walk briskly, like you're an important person and you're late for a meeting. Do not run. Running is suspicious. Do not look back to see how close a pursuer might be. If they catch you, you'll know.
Nowadays, it's suspicious to not have a cell phone, so bring a phone that isn't activated anymore, (maybe purchased with cash at a pawn shop) and fiddle with that while you hunt.
Don't bring your actual phone; it will ping your location when it connects to cell phone towers. If the police try to connect you to the last known location of the trophy, that's the first thing they'll check. It'll show you were home, and if they're typicals, they'll just move on to the next suspect. Might be tricky if somebody calls or texts during that time and you didn't respond. But it's probably fine. Nobody ever calls you anyway.
Fortune favors the prepared, and good luck is the residue of good planning. Remember, wherever there are people, there is the potential to be practicing.
Happy Hunting.
THE END