We had good success on the Nova Forum in critiquing observers and improving the photometry. Unfortunately, Nova Del is in its nebular phase, which means almost all of the flux from the star is through emission lines. These make comparison between observers almost impossible, as you can't transform cleanly and your particular filter/camera/telescope combination may have a different throughput for the various emission lines than is the case for the next observer. Continue observing it (please!), but perhaps it would be good to choose another star for critiquing observers.
So I'm going to have a few test stars over the next year, and I offer my expertise in critiquing your observations. These test stars will be non-pathological: no emission lines, no strong molecular absorption lines, no flickering. This limits us to primarily regular pulsators and eclipsing binary stars. However, the goal is for everyone to submit observations that fall within 0.01-0.02mag of everyone else. It can be done!
Rule number 1: you have to make your observations as "sets", with a minimum of 3 images per filter. Results need to be averaged and the report needs to be the average value and the standard deviation from that value. I'll post Richard Sabo's Windows program on the website as a helpful tool.
Rule number 2: you can do single star or ensemble, as the comparison stars for these field have well-determined magnitudes and colors.
Rule number 3: you need to observe in at least two standard filters. I'd choose B and V as the best; V and Ic as second best; any number of filters is ok. I'll probably do BVRI myself, but may include Johnson U, for example.
Rule number 4: you need to transform your data. This is the hardest part of the experiment. You can post untransformed data at the beginning, but learn how to transform, get your coefficients, and replace the untransformed data with properly transformed data before long.
The first object: XZ Cet. This is classified as an anomalous cepheid, with a period of 0.823 days. At 2hrs RA, it is an early evening object. You do not need to have a cadence of more than 10-15 minutes, and once/hour or evena couple of times per night is fine. So you can go off doing other projects inbetween your measures. I've posted a comparison star sequence. None of the stars is comparable in brightness to the target, but you can adjust your exposures so that the target is not saturated, yet you have good signal/noise in at least one comp. Note that most of the comps are to the east/northeast of the variable, so you might want to offset the variable in the field to pick up comparison stars. The variable is 9th magnitude, so watch out for scintillation; it is at -16 Dec, so don't observe past 2-3 airmasses (that in itself may limit how long you follow it!).
Good luck! As observations are submitted, I'll post on this thread any comments that I might have. I expect others to contribute their views as well! If you don't like this star, wait for a month or two and I'll have another one for you.