1. Verbs has to agree with their subjects.
2. Prepositions are not words to end sentences with.
3. And don't start a sentence with a conjunction.
4. It is wrong to ever split an infinitive.
5. Avoid clichés like the plague. (They're old hat.)
6. Be more or less specific.
7. Parenthetical remarks (however relevant) are (usually) unnecessary.
8. Also, too, never ever use repetitive redundancies.
9. No sentence fragments.
10. Don't use no double negatives.
11. Proofread carefully to see if you any words out.

On a more serious note, it is important that students learn to write well. Here are several items of advice regarding technical writing:

• The subject and verb must agree. ("A group of tests was performed ... The data were plotted ...")
• Past tense, third person must be used consistently. ("... velocity was measured with the probe ... pressure was measured ... viscosity was calculated ... data were obtained ...")
• "Data" is a plural word. ("Data were recorded at two downstream locations ... these data are plotted ...") Many authors treat "data" as a singular word ("... this data is useful...") incorrectly, e.g., "... this data is useful...". The word "datum" is intended for a single data point.
• The plural word "they" should not be used as a neuter singular subject. (Incorrect: "If a student does this, they will learn that ..." Correct: "If a student does this, he/she will learn that ...")
• Sentences should not end with prepositions like "to", "at", "in", etc. (Incorrect: "... the chair I sat on." Correct: "the chair on which I sat.")