Investing in the right tools makes a huge difference. Quality brushes DO make a difference. Every paint brand has its strengths and weaknesses, don't hesitate to pick up different brands and know the differences to see what works best for your style. The proper paint for your style and look will make your job so much easier!
Don't be afraid to put yourself out there, share your work, ask questions. The painting community is a very supportive one. Everyone has an opinion, and thanks to social media, they are eager to share it. Take that feedback, positive or negative, and use it to become a better painter. Let them tell you what you do well and expand on that.
Immerse yourself in learning. There are so many resources available out there, youtube, facebook, instagram, etc and plenty of painters willing to share. Watch videos, read blogs, study photos, and most importantly, experiment! There is no point you cannot recover from with a new coat of paint
Don't try to paint like someone else. Take those techniques and adapt them to your style. Do what you do best, perfect that. I think of it like putting an outfit together. We are all given the same basic "wardrobe" of techniques. Its how we combine them and wear them that sets painters apart.
Your finish is only as good as your prep. Learn how to "read" your piece, analyze what it needs before laying paint on. Create a mental flow chart, "if this, then that". Know what products are available and when you need them.