I used flash cards which came monthly - it was over 40 years ago and I can't remember what they were called, but each card had a picture, with a matching word card.
At first, my daughter learned to name the picture - cat, pig, dog, etc and I put the correct word card with the picture.
Eventually she was able to name the correct word card without the picture.
Then I started her on the Peter and Jane books.
She had read the whole series before she started school, aged 4. (It was a private school that took children from the age of 4).
When she joined the school, they put her on free reading books, as it was obvious that she was a very fluent reader. (When I say fluent I mean that she was able to read newspapers).
It could be that she was very gifted in language - she grew up to speak 3 languages and worked as an interpreter.
So, Peter and Jane worked well for her, and I started using them to reach my granddaughter to read. Her school was amazed at her reading ability from reception onwards. She is now year 3 and many of the other children have caught up with her.
She too is orientated towards English but she is far less confident in maths, as was her mum.