So the first method i started using was
Going Old School -
A Binder and some Paper i just write the title and the author then the date i started and finished the book.
I also do this for my haul because i never can remember what books i got when...
Method 2
Post It Note -
When ever i just want a quick glance at when i finished or started a book i just look in the inside cover and see because you can remove a post it note with no damage to the paper. I divide the post it not into 4 or 5 sections then i use it kind of like a library sticker but not then i know the first time it read it was this date the second was that date and so on and so forth....
Method 3
Using a Diary -
Just using a yearly diary, i just write when i started and the the date i finished the book its pretty easy to understand
The final Method
Method 4
Libib -
So libib is an free app i got from google play stores i was trying to find a app that catalogues books from there barcode and this was the most recommended one. so all you do is make a library so i have TBR, and Read Books and all i do when i get a new book gut scan the barcode into the library you want it to go. so you can keep track of all of the books you own.
Hope some of this helps you
Until Next Time
Happy Reading