Deviantart has some decent tutorials if you're looking for them!
The best way to improve, for me at least, is to draw from photos. The more you draw from them, the more you can see how animal subjects look anatomy-wise and you kinda "memorize" their anatomy from practice. Then you can play off that to develop your own distinct style.
One way of simplifying anatomy is to understand the body as a series of shapes. Break down an animals body as a bunch of simplified, but prominent shapes. What's the simplest way you can render an animal without totally drawing it out? Aka, what shapes can you mash to show a tiger, without drawing it out fully?
example for my dino
Then, after the shape, you can set about refining it and adding details. Google is your best friend for this! You can also start from a skeleton and try to "build" up to its final shape.
Linework is all about knowing the exact path of the line you're drawing and using the least possible strokes for that line. It's more a personal "feel" sort of thing, so it really depends on what you want. Drawing with pens or permanent markers a lot can help with improving line quality since you can see every line you make and aren't tempted to erase. This will teach you to have a steady and sure hand for lining.
Coloring is another personal feel thing. Is there a particular style of coloring you like? I'm a self-taught artist so I'm a little bit clueless on color theory, but there are certain styles I really like and incorporate into my own stuff.
For example- Van Gogh's style enunciates brushstrokes so that each brushstroke is basically a different color and you can very clearly see the stroke on the painting. Each one is very distinct and that is a quality I very much like.
I actually had the chance to see a few of his paintings irl, and you can even see the paint piled up on the edges of the strokes that add to its "solid" quality. These observations were just something I kept in mind for adding to my own style.
You're going to find how you draw is going to evolve all the time and that's totally fine, too!
Hope this helps!
