None seem appropriate. If you write down the procedures, etc., you write them. If you document them with pictures, it's not in writing.
Grammatically, they are all okay. They might be better if you said THE process or procedure, meaning the specific one(s) you used.
1. To complete the report, you should write down preparation materials and experiment process with pictures.
2. To complete the report, you should write down preparation materials and testing process with pictures.
3. To complete the report, you should write down preparation materials and experiment procedure with pictures.
4. To complete the report, you should write down preparation materials and testing procedure with pictures.
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I have made sentences in several ways. Which terms do we have to use? Would you let me know appropriate English terms?
3 answers
I would change the verbs:
... list the preparation materials ...
... describe the testing process and include pictures ...
... describe the experiment procedure and include pictures ...
... list the preparation materials ...
... describe the testing process and include pictures ...
... describe the experiment procedure and include pictures ...
That would be better, yes, Writeacher. I assumed an either/or, written or photographic documentation. Today, some things are told only in video/pictures. Both would be a more complete description of the experiment.