Agree.. I think the most effective way is read aloud with parents
I read the Usbourne young reader book set (50 books) with my girl during the summer and now she (K2) can read almost all of it (the more difficult ones she can read 80 percent) and we have more topics to talk abt...
In fact, if you have time, you can have better result when you read with your children for about 15 minutes every day. This is very true. You can try. They love reading with you.