I'm a big fan of making lots of cards, like you say you can just hit Easy and send them into next year, or conversely if you keep forgetting them and they're using up lots of time, just suspend or delete them.

When I couldn't remember a particular kanji in Japanese I used to make lots of cards that featured that kanji at the same time, and usually I'd review them all the same time, it's sort of cheating but it always seemed to help me remember the kanji in the end.

It's actually the correct way to make that work. Some Hanzi and Kanji are really abstract and are best learned by associating it with multiple related concepts. Each can have dozens of very distinctive meanings.

Yeah I learned pretty much every kanji with jukugo (did Remembering the Kanji at first, but it wasn't that helpful). A lot of failed cards at first since I was trying to learn recognition of the kanji, the kana reading and the word's meaning - but it got easier over time.

The only disadvantage I may see to this is that it skews your counter of daily cards. So you may feel discouraged if you see that you have a large amount of cards to review and that it will probably take you a lot of time to go through them all, while in fact, you will only spend a few seconds on those that you already remember. Unfortunately, there are times when I cannot for the life of me do my flashcards because there are too many of them to review, and I either skip that day's session because a) I tell myself I don't have enough time (which is a lie most of the time!) or b) I don't have the mental energy to go through them. The only (partial) solution I have found to that is doing them first thing in the morning by trying to plan my schedule accordingly and wake up a tad earlier.

Use the setting to limit the number of daily cards when you find the number bothers you or you’re too busy. You can change it often, too.

A low limit will mean some cards don’t hit on the optimal day, but you’ll eventually have time for every card once enough of them have been recalled a few times.

I have configured a review session to be at most 15 flashcards or 5 minutes, whichever is shorter. It usually takes 2–3 minutes. Often I do multiple review sessions back to back. But I'm only ever committing to 15 cards at a time, regardless of the size of the backlog – that is very manageable.

I would actually advise against it, or at least take the approach of removing cards that are too easy. I remember reading some article about spending your time learning stuff that is "just hard enough". When you study things that are easy you are kind of wasting time, you want to the material to be +1 in difficulty what you already know, not +0, not +250. While the easy questions give you satisfaction, they aren't helping you actually learn. I would argue that multiple cards on the same subject end up equating to a bunch of time wasting easy cards.

The disclosure to this is that I also don't think you should spend a lot of time figuring out how to create cards. There is some payoff in optimizing the process, but focus on just making the cards and reviewing them so you are learning the actual target subject.

All that said, my current approach is to create cards for concepts that I think are a little hard to understand or that I know I won't see enough repetition in daily work/tasks. If I find out after a few weeks the cards are too easy or too similar I usually with just delete it.

I don't think this really makes much of a difference. At least for me it didn't. Sometimes I remove cards that are too easy, sometimes I see that the next time to review them would be 6 months down the line and I leave it in, because the cost of leaving it is so small.

What has made a difference though is thinking about wether I still actually want to remember the contents of a card. Sometimes a card comes up that I haven't seen in months and I think "you know what, I haven't thought about this at all outside of Anki and I don't think that'll change." and then I just remove it. Sometimes I create a nearly identical card again later on, sometimes I really didn't need to know something.