From my experience it more helpful to understand the principle your missing behind the items you can’t pin point which is which than to drill them, that way you’d be able to use the same principles for future pairs.
With verbs reading The Definitive Guide to WaniKani's Transitivity Pairs may help you identify the meaning using the verb structure.
Combine these with a phrase that is meaningful for you which will put it in context and you’ll be able to use it every time you see a verb. It can be something someone says in an anime, a tv show, a song, a book whatever works for you. Better than drilling, since it gives meaning and purpose to the structure itself.
As for the 体 and 休 and other similar to kanji, the problem usually stems from either not taking enough time to pay to details when doing the lesson and perhaps not clicking with the mnemonics, or not being exposed to enough Japanese in the wild. If you look at those particular couple one has the book radical and one has the tree radical, the different between the is one little extra stroke. So the question is what will work best for you - associating the difference to the number of strokes, the radical meaning or perhaps a word that one of them build and you do remember. Some leeches need more attention to details, some leeches will sort themselves while you read some leeches won’t and that is also okay.
Drilling without exploring if there is an actual reason for your inability to distinguish similar looking words/kanji will cement bad learning habits something that many independent language learners suffer from myself included.