I’ve experimented with Anki over the years and currently have a somewhat custom setup that I do every day / nearly every day. I’ll explain below for anyone that might find it useful.
At one point I realized that my capacity for learning new items for a particular topic is limited to a few items per day. Any more than 2 or 3 and I struggle to retain the information. So, for example, trying to learn 20 words in Chinese per day is impossible without spending multiple hours on it.
The trick, however, is that I get around this by having many items from multiple topics, instead of many items from a single topic. Instead of 20 words in Chinese, I learn 1 word each in 20 different languages. Surprisingly, I have a much easier time with this and don’t need to spend much time on it in order to retain the information. I don’t know why this psychologically works, but it does. And while learning 2 or 3 words a day won’t make you fluent anytime soon, it does add up over time, especially for topics that you aren’t in a hurry to learn but would like to know on a slow timeline, in a year or two. For example, learning the Japanese hiragana/katakana or the numbers of all the US presidents.
However, this proved to be somewhat unwieldy logistically as I had to open 20 different PDFs, download audio for each word, then stitch it all together daily. So I created a little web app (stitched together from some WordPress plugins, actually) that allows me to import learning materials and then display 2-3 of them per topic on a single page, each time the page is loaded. I just visit the page once a day and add the items to Anki.
This was all a bit complex to set up, but if you enjoy learning new things and want an efficient system for adding stuff into your brain, I recommend making something similar.