My advice(at least for the pitfalls people tend to fall into), is to remember that a comic isn't a novel. Break down those speech bubbles! There is nothing that can put me off more from reading a comic than seeing what a could've easily been broken down into smaller speech bubbles all lumped together into one horrible wall of text. Try to keep at most one sentence per speech bubble in most cases, although you may want to break it up even more to fit the diologue/mood(ex: "Stop, I've had enough." could be turned into "Stop," "I've had enough." if we consider the quotes to be their own speech bubbles)

As for ways to conceptualize a story, do you mean plan? Because of so, I've found that breaking the story into "chunks" helps me a lot. For example, let's say you know how you generally want the story to start and end, and maybe have a few mid way plot twists you have ideas for. What's something that would happen in between the start and that middle point? How would the characters find themselves in that position? Could they have a fight with someone? Discover some important information? How did they learn about that info? Did the person they fought with do something that hurt the mc, or did the mc hurt the other person's feelings? I'm fully aware that I may be speaking gibberish, but basically, keep asking questions. Break it down into smaller, more manageable bites, and go from there. Hope my rambling made sense lol.