I've been trying to improve my latte art the last couple of weeks and as someone who generally prefers straight espresso to milk drinks, I don't have a lot of opportunity to practice with actual coffee/milk. What finally led me to a breakthrough (after watching good tutorials) has just been practicing pouring tap water into other tap water. While it might not give you much visual feedback, it does allow you to practice technique endlessly until it becomes muscle memory. I think the main reason most of us struggle with latte art in a home environment is you are never going to produce the volume of drinks in rapid succession required to imprint the technique into muscle memory. With water you can practice pouring 5x in a minute.

Focus on one part of the pouring technique, and once you feel like you've gotten it down, watch the tutorial again and focus on a different part. The other general piece of advice I would offer is pour slower.

Poured this rosetta this afternoon, it's certainly not perfect, but it's progress: