There's a long standing joke to "thin your paints!"
Check out this guy's post about it: https://ageofminiatures.com/thin-your-paints/ and you can see some of the changes that it offers.
It also doesn't look like you've applied a wash yet, and doing that is a really simple way to add an incredible amount of detail--or, I guess, it makes the details of the model really pop by adding shade to all the little nooks and crannies. Those two models both look like they will show huge benefits from a good wash.
The striping you did on that first one is really cool. If you've got the hand to paint those spots without blurry lines or your hand shaking everywhere, I think you're on a great path for painting minis.