Branding may seem like something you can overlook or not worry about, but the truth is, it's one of the first things artists should tackle, especially with so much movement to online sale portals and galleries. There is a ton to discuss on this topic, and I'm just touching on it here.
Branding does not have to be complicated. In fact, the simpler the better.
What is branding? It's your mark, your look, your visual signature. It's what speaks for you when you cannot. It incorporates your logo (or the font you use for your name), it is a color palette, fonts and also a feeling conveyed to the viewer. Take for example, Coca-Cola. Their logo and the color red are part of their branding. It is instantly recognizable. Branding separates Coke from the other colas out there, just like actual cattle branding separated cows from other cows.
So you should develop your branding first, and use it on everything that the public will see. From business cards to online, to social media, to any kind of advertising. As mentioned above, it's to speak for you when you cannot. It should convey a feeling, and if done well, instantly recognizable.
How to do this as an artist? Start with a typeface that your name will always be in. Choose a limited palette of 2-3 colors that are the only colors you will use in graphics. Select a font you will always use for headings, and another for body copy. Commit to it. Don't overthink it. And use it everywhere.
Some good design tips would be: your branding compliments, not overpowers your artwork. It is clean and professional. It is consistent and uncomplicated.
A good way to research good branding for artists is to study high end gallery websites and advertising. Less is more is the common thread.
You should start with your website (I recommend Squarespace) and build everything else from there, based on your website design.