The Formal Report
The procedure is there for someone to replicate your work and its result. It should be a clear, concise description of the actual procedure used in attaining the data. It is accompanied by figures and diagrams that make it clear how the experiment was set up and run. It does not contain any instructions. Also, it does not contain any statements about what might have been done, or what should be done (such considerations are reserved for the Discussion section).
The procedure must be written as a statement of what you actually did (past tense). It must be written in paragraph form (not point form). The procedure will describe only what is relevant to the outcome of your report (in answering its objective). It must not contain instructions or suggestions of any kind. It must not contain Data and not contain Results.
A diagram of the experimental setup is required in the procedure section. The diagram is a hand or computer drawn visualization of the setup. It is not a photograph. This diagram differs from diagrams in the introduction as it shows how the equipment is set up. Color may be used in your diagram to enhance legibility.
Once written, consider if someone else would be able to do exactly what you did after having read your report. This includes selecting the same equipment you used, setting up the experiment the same way you did, and taking the same steps you took in the order you took them. This is a lofty goal that is never met entirely. Seemingly insignificant differences in the procedure can have a dramatic impact on the results (sometimes good, often bad). Good reporting in the Procedure section allows for better planning to solve mysteries and improve procedures.
Diagrams provide enough detail to assist in setting up the apparatus in the same fashion that you set your apparatus up. Sometimes several simpler diagrams serve the purpose better than one detailed one.
Diagrams are not sketched. A straight edge is used for drawing all straight lines. Curves are drawn with a spline or other instrument. Items are not over-written or struck out (white-out is permitted). The scale of items throughout are consistent.