As you get deeper in, you start making associations and recognising patterns, and it gets much easier. It's like trying to memorize telephone numbers at first, though.

I recommend just using the sentence -> reading + meaning + picture + audio cards only, as the complete sentence gives you more exposure to the combinations, and more context to hook onto. Also provides kana practice.

Listening carefully to the sentence audio, replaying it a few times in your "mind's ear", and speaking it aloud provides some useful auditory context. Also studying the picture.

Anki's default settings for 'ease' and 'steps' are rather optimistic. I prefer to use something like ease = 150%, steps = 40 80 120 240 (similarly for 'lapses').

For difficult cards with long kun readings, try focusing on recalling just a single kana letter at first. I usually find the one nearest the okurigana is easiest. The remaining letters then become easier.

I found some visual imagery for some of the readings useful too. E.g. しゅう -> shoe. Doing RTK laid the groundwork for this.

I also used any lame coincidence in the sentence as a cue. E.g. if the target word starts with the same letter as another word in the sentence etc.

HTH