How can I intertwine something happening in real life and incorporate a dream while it’s happening? and write them together for the same scene?
How are they happening at the same time? Is the person remembering the dream while experiencing the waking-life event?
Ok, that's pretty straightforward then. It happens to me frequently. I'll do something in the morning, or later in the day, and suddenly I'm reminded of a dream I had in the night. And often it isn't because anything I'm doing explicitly reminds me of the dream, but sometimes it is. That would probably be helpful in a story. For instance, the character is pouring milk on his corn flakes and has a sudden very vivid memory of the dream, in which he saw a demonic-looking arm pouring a chalice full of blood onto a goat being prepared for sacrifice. Or whatever your situation is of course. And unless you want to take away all the mystery and power of dreams, I wouldn't immediately say "he remembered the dream had had, where he saw a demonic arm..." That just kills all the power of it. Keep in mind that while you're experiencing a dream it's absolutely real, and that they don't follow the logic and causal reactions of normal waking life, so miraculous and powerful things can happen. Also, often when remembering a dream, you're confused briefly about when/where this happened to you. It might take a moment to realize it was a dream, at first you just remember the event and the power of it. So maybe something like— 'He was pouring milk on his cereal when suddenly he was overpowered by an intense vision. It struck with the power and vividness of a dream, and he was certain he had actually seen it recently somewhere, but was at a loss to remember where or when. An arm, long and almost skeletal, flesh sunken and wattled with heavy wrinkles or folds, and a surface texture—could it be tiny scales? It held a pitcher, or no, it was a chalice, and it was pouring some dark liquid slowly, moving in regular circles in a ritualistic manner. Below it lay a lamb or a goat or something, nearly unconscious on a stone altar dark with ancient blood. He had to make an effort to return to reality. He had started to pour milk on the table when the bowl overflowed. What the hell was going on? What was this weird vision, and why did it have such intense power, as if it were absolutely real? Yes, he had seen it recently, in fact it was in a dream the night before. It began to flood back and its power overwhelmed him once more. His cereal sat uneaten, and half an hour later he dumped it in the garbage disposal. He didn't feel capable of eating right now.'
