How to place the points
Each row is one point. The first number is X. The second is Y. You do not need a label on every point. A group assigns the point to a series, and the series name becomes the legend. Two groups are enough for a comparison, such as two classes or two products. A third and fourth are available. More groups than that turn the plot into a color key nobody can hold in memory. Add a row for another observation. Delete a row that was a typo.
Name the axes with the units. Hours and Score, or Price and Weight. A scatter plot without units is a decoration. The chart pads the range so points do not sit on the frame. Set a Y minimum or maximum only when you must match another figure. Cropping an axis to exaggerate a slope is a good way to mislead, including yourself.
Point size is a drawing choice, not a third measurement. Make points large enough to see and small enough that a cluster does not become one blob. If many points share the exact same pair, they stack and look like one point. That is a limit of this chart. Jitter is not applied. If ties are common, say so in the subtitle or move the counts into a table.
There is no line of best fit on this page. The plot shows the cloud. You can see a rise, a fall, a fan shape, or no pattern. Do not claim a cause because the cloud leans. The subtitle can describe the sample, such as one class in May, so the reader knows how far the picture extends. Grid lines help when someone will estimate a coordinate. Turn them off for a cleaner figure once the shape is the only message.
Export PDF for a report, PNG for a slide with sharp axis titles, and JPEG if needed. If the horizontal axis is time and each row is the next month of one series, use the line chart so the order is drawn as a path. If you have one list of numbers and you want the shape of their spread, use the histogram. The points are saved in this browser and nowhere else.