1 - Not having a plan.
Don't wing it. Please sit down and write out what you're actually trying to accomplish with the stuff you're posting. Otherwise it's just noise. Are you trying to generate sales? Make offers. Are you trying to build your audience? Add value and ask for shares (Tap the paper airplane and share this in your story). Figure out what a win looks like and then win.
2 - Not tracking your results.
Based on what your win looks like, what numbers do you need to know to see if you're moving in the right direction? Figure that out, and then you can actually evaluate.
3 - Not posting native to the network.
Don't act the same on Instagram as you do on LinkedIn. Unless you'd like people to completely ignore you on the one you're screwing up.
4 - Putting your head in the sand.
When people comment, answer. When people don't get what they need from you, make it right for them as much as you can. Don't ignore the problems. Address them.
5 - Talking to the wrong person.
You have an audience of one. One person, your ideal customer, that person you'd most like to serve. When you turn the camera on, you're not talking to the camera, you're talking to them. Act like it.
6 - Being sketchy.
You post 3 times a day for 5 days and then you disappear for 2 weeks and then you post once and then you're gone for 5 days before the next one. You're unreliable, and people don't want to spend their time with unreliable people. Be where you said you would. Be consistent.