Art is a tough subject to give tips, but I think there is some advice I have. If you want to improve, you should always try new things. You can try mimicking other people and learn what they do. By doing so, you can gather different techniques which can help you discover more and more about art. Some people may be against this, but I believe that art stems from inspiration, whether it be from real life or others.
Try new things and keep at it. That is the way of the artist.

I has been notice. Thanks Tv-senpai! One more thing.. Coloring advice! Same thing like your advice or different?

I feel like coloring is a beast of its own, and I've seen many people go about it in various. Something I've learned through observing others is that using different colors gives things a more vibrant feel. Its a little hard to explain in words, but here's an example:
Say you color an apple red. You can use a darker red to give it dimension and depth. Rather than using another shade of red, you can use purple and erase the opacity until you are satisfied with the color. It gives things a brighter, vibrant look. Some colors go better with others, but to figure it out, you need to experiment. Color is a hard subject, and i feel like i still have much to learn, but that is some knowledge I have on the subject. I hope i wasn't to confusing. Good luck with your art!