Default settings are ok although I'd say 2 things that are counter to some common advice there:

* Actually use all 4 ratings buttons, and come up with a scheme for when. For me it was 1: missed it, 2: had to guess, but guessed right, 3: got it, 4: got it without even reading the entire prompt

* If you're insistent on the (IMO bad advice) "only use 1 and 3 keys" thing, install the "Straight Rewards" plugin. Without it, all your ease factors will decay to their lowest level (130% by default) since '1' lowers it, but '3' does not raise it, so it can only go down. With "Straight Rewards", it'll up the ease factor for you gently as you rate a card '3' enough times in a row.

Alternately, install the FSRS4Anki plugin. It's more work, but is a more dynamic scheduler. Requires the V3 Anki scheduler being enabled, and one of the more later versions. Do some reading on this before you try it; you can always go back, but it's not been proven yet to be substantially better than SM2.