So while aside from 2 (where as you called out yourself, you weren't using cast shadow shapes) you're generally moving in the right direction, the main thing you'll want to keep working towards is reducing your reliance on having to outline your forms first. That's basically the big challenge surrounding texture - it's really hard, but we want to keep working on being able to hold our understanding of a given textural form and its immediate surroundings firmly enough in our heads to be able to draw the specific cast shadow shape it'll draw, and to see if we can actually capture all those shadows without relying on any outlining.

Even though this isn't tire related, this example of a bush viper's scales may help. Note how none of the scales are outlined (except where they break the form's own silhouette) - we're only looking at the shadows that they'd cast, and nothing else.