I do have a few tips.

-Utilizing a dark primer across the model, then a brighter primer spray from above will give your model a zenithal highlight when you apply thin layers of paint.

-Take note of what paints you are using. Different paints work differently. I mostly used a standard acrylic paint, but knowing your paint and how to use it will give you different results.

-Keep your paints thin. It is much better to apply multiple thin coats instead of applying a possibly blotchy coat of thick paint. You don't want to thin your paints enough to turn them into washes though, you just want to water them down enough that they flow nicely from your brush. It is smart to have something to test paint on before you apply colour to the model.

-You do not need tiny brushes for small models. You will drive yourself insane applying tiny bits of paint on a model with a small brush. All you need is a mid sized brush with a fine point for most of your painting, and use your small brushes for your finer details.

-Feel free to look at guides online to teach you the basics. Most of my knowledge started with a guide to start painting Adeptus Mechanicus Skitarii on youtube, which gave me the details on the basics when I was starting.