When you don't know what you're doing, do it neatly. Experiments must be reproduceable, they should fail the same way each time. First draw your curves, then plot your data.
Experience is directly proportional to equipment ruined.
A record of data is essential, it shows you were working. To study a subject best, understand it thoroughly before you start. To do a lab really well, have your report done well in advance. If you can't get the answer in the usual manner, start at the answer and derive the question. If that doesn't work, start at both ends and try to find a common middle.