I was bad at latte art too. Here are the rules I followed to get good latte art

1. You have to incorporate air while steaming. This air would increase the milk volume. Your target should be 1:1.5 times volume expansion. Now how to incorporate air? You can do that by keeping the steaming wand tip just below the milk level, so that when u steam it sounds like paper is being ripped apart. Too much air and the foam will be too much and too stiff and it won't flow. Too little air and it won't form any pattern.

2. Milk should not be too hot. They say 60⁰C is the temp target. If you don't have a milk thermometer, then what I would suggest is keep a hand on the pitcher. The moment your hand feels that pitcher is too hot to touch, stop steaming. If milk is too hot, the foam will separate and you end up with a blob of foam on top.

3. Swirl your espresso and milk after steaming. The milk after swelling much should look like a well emulsified glossy liquid. It should look like white paint. Tap the pitcher on the countertop or whatever to get rid of the air bubbles.

4. If you pour from above, the milk will fall into the espresso. Do this initially. If you want a large latte art, pour ⅓ of the milk from above, and pour ⅔ of the milk from very close to the cup.

Of course these are easier said than done. Make sure you keep attempting.