Gretchen Leigh

As far as long dialogue, two lines at most on screen is standard. If it goes longer than that, you just need to find a natural place to put a break in the sentence and continue it in the next sub line. You don’t need to connect two sub lines with ellipses. A comma can help indicate the break but is not required. Also, if you let Aegisub handle the styling, it’ll sometimes style the two lines on screen strangely - such as the top one being significantly longer - so put in an enter to tidy that up if necessary. Also, make sure you have a buffer around the sides so that your subs don’t run all the way to the edge of the video, but I don’t remember what our buffer is off the top of my head so I can’t advise you of that.

Also, it’s tangentially related to line structre, but you should avoid going over 20 characters per second as much as possible - Aegisub will display this by default. 20 is the maximum to be able to be read comfortably. An occasional 22 or whatever is fine if you really can’t bring the CPS count under, but avoid it as much as possible.

As far as fonts go, a well-weighted sans serif is standard. Some people use drop shadows to make subs stand out more; my group doesn’t. Outlines are necessary - I think we have ours at 4pt? Your font should also be quite big - we sit around 50pt for 1080p videos. You can honestly get away with Arial if you really hate searching for fonts. We’ve always used LT Finnegan Medium, and while it’s not the universal fansub standard, you’ve probably seen it in subs before if you regularly watch fansubbed anime - it’s a total workhorse that goes well with anything and is very easy to read.

I think that covers it!