Part 2: Data points
Data points - oh mystery of data points! Hide them well, and don’t confuse the issue by using different symbols for different data sets.
Good style is to omit the data points, but only draw a wiggly curve that starts and ends somewhere for no apparent reason. Claim that there once were data points under the curve, but the whiteboard marker pen that you used to draw the curve obviously makes it hard to see the data points which were put in by pencil.
If you connect the data points, do so in random order. Impress your tutor with your thorough understanding of quantum electrodynamics when you allow data points to go back in time. Having the occasional loop in the your graph looks cool too.
Use wiggly curves to connect the data points; this leaves you room for interpretation. Continue your wiggly curve far beyond the data points, this way you demonstrate that you know what the data would be like if you had measured them, which, in fact, is why you didn’t bother measuring them in the first place.