In order to establish a professional online presence, there are a few things you should do. Some of which are outlined below.
1) Engage. Don't ignore your customers. Engage with them. Whether that's in comments of a post on social media, or messages to a social networking account, or in other ways of communication.
2) Produce Quality Content. Don't rush. Don't compromise your integrity. Always put your all behind your content. Customers will appreciate this.
3) Widespread. Don't just stick to one social networking account. Despite where you think your target audience 'hangs out', be widespread. Expand your outreach.
4) Establish Target Audience. How can you create marketing campaigns, create good copy with wording that's appealing to your audience, if you don't know who your audience is? PLUS: A benefit of this is when you know who your audience is you can post on the social networking accounts they are mostly on, and at the times they tend to be active.
5) Conduct yourself professionally and politely. Never argue, insult or patronise, or rant politics. Be entertaining, informative, and memorable.
Good luck from Thomas Author Services!