I used to do almost nothing Monday to Friday, then try to make up for it with two or three hours on Sunday. It felt productive because Sunday was a proper study session, but I kept spending the first half remembering what I had forgotten.
For the last month I have done about 20 minutes after dinner on weekdays: a little listening, a few flashcards, occasionally writing five sentences. The total time is not dramatically higher, but the language feels less like something I reopen once a week.
The annoying discovery is that boring consistency may actually work.