Language mentor Lýdia Machová, who helps people teach themselves foreign languages, often recommends the use of parallel texts. These are books in which each page of a foreign-language work is printed alongside its translation.
In some cases, like that of the component volumes of the Loeb Classical Library, parallel texts are printed as such. In others, the language learner must assemble them for himself. (In the age when both the original versions of many books and their translations can be found on sites like The Internet Archive, this is largely a matter of cutting pages out of PDFs and pasting them onto presentation software slides.)