I have been learning material by using a combination of repetition and my variation of The Feynman Technique.
My strategy is to repeat the material in chunks, i.e. section 1, then section 1 and 2, then sections 1 through 3, sections 1 through 4, etc.
I try to paraphrase every sentence. Sometimes it’s I just reverse the sentences, sometimes I change them into a question and answer, and sometimes I just use synonyms for a word or for multiple words in the sentence.
I think this has been working for me because of the sheer number of repetitions, but also because I am actively engaging with the material, and I am jamming the information into my working memory. Furthermore, I am exposing myself to the material in many different ways because I probably paraphrase things slight differently each time.
I think if I get comfortable with the earlier sections, I might start reviewing from the later sections. For instance, if there are 10 sections, I might review section 10, then section 9 through 10, then 8 through 10, etc.
I think I can certain material into long term memory by using flash card software. Also for things that just have to be memorized, I can create pictures, patterns, stories, rhymes, or use memory techniques such as The Link Method.